I can confirm this - has been happening ever since my clean Tribe 4 install; but not on every boot. Sometimes sound will come up muted, sometimes not. It came up muted on this boot. Attachments as requested.

Linux craigus-desktop-ubuntu 2.6.22-14-generic #1 SMP Wed Oct 10 06:00:47 GMT 2007 i686 GNU/Linux

aplay --list-devices
**** List of PLAYBACK Hardware Devices ****
card 0: I82801DBICH4 [Intel 82801DB-ICH4], device 0: Intel ICH [Intel 82801DB-ICH4]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: I82801DBICH4 [Intel 82801DB-ICH4], device 4: Intel ICH - IEC958 [Intel 82801DB-ICH4 - IEC958]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

tail -2 /proc/asound/oss/sndstat
0: SigmaTel STAC9750,51
1: mixer10

amixer
Simple mixer control 'Master',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 0 [0%] [-46.50dB] [off]
  Front Right: Playback 0 [0%] [-46.50dB] [off]
Simple mixer control 'Master Mono',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 31
  Mono: Playback 25 [81%] [-9.00dB] [on]
Simple mixer control 'Headphone',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 0 [0%] [-46.50dB] [off]
  Front Right: Playback 0 [0%] [-46.50dB] [off]
Simple mixer control '3D Control - Center',0
  Capabilities: volume volume-joined
  Playback channels: Mono
  Capture channels: Mono
  Limits: 0 - 15
  Mono: 0 [0%]
Simple mixer control '3D Control - Depth',0
  Capabilities: volume volume-joined
  Playback channels: Mono
  Capture channels: Mono
  Limits: 0 - 15
  Mono: 0 [0%]
Simple mixer control '3D Control - Switch',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'PCM',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 0 [0%] [-34.50dB] [off]
  Front Right: Playback 0 [0%] [-34.50dB] [off]
Simple mixer control 'PCM Out Path & Mute',0
  Capabilities: enum
  Items: 'pre 3D' 'post 3D'
  Item0: 'pre 3D'
Simple mixer control 'Line',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 0 [0%] [-34.50dB] [off] Capture [off]
  Front Right: Playback 0 [0%] [-34.50dB] [off] Capture [off]
Simple mixer control 'CD',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 0 [0%] [-34.50dB] [off] Capture [off]
  Front Right: Playback 0 [0%] [-34.50dB] [off] Capture [off]
Simple mixer control 'Mic',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Mono
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono: Playback 0 [0%] [-34.50dB] [off]
  Front Left: Capture [on]
  Front Right: Capture [on]
Simple mixer control 'Mic Boost (+20dB)',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'Mic Select',0
  Capabilities: enum
  Items: 'Mic1' 'Mic2'
  Item0: 'Mic1'
Simple mixer control 'Video',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 0 [0%] [-34.50dB] [off] Capture [off]
  Front Right: Playback 0 [0%] [-34.50dB] [off] Capture [off]
Simple mixer control 'Phone',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Mono
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono: Playback 0 [0%] [-34.50dB] [off]
  Front Left: Capture [off]
  Front Right: Capture [off]
Simple mixer control 'IEC958',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'IEC958 Playback AC97-SPSA',0
  Capabilities: volume volume-joined
  Playback channels: Mono
  Capture channels: Mono
  Limits: 0 - 3
  Mono: 0 [0%]
Simple mixer control 'PC Speaker',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined
  Playback channels: Mono
  Limits: Playback 0 - 15
  Mono: Playback 0 [0%] [-45.00dB] [on]
Simple mixer control 'Aux',0
  Capabilities: pvolume pswitch pswitch-joined cswitch cswitch-exclusive
  Capture exclusive group: 0
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Front Left: Playback 0 [0%] [-34.50dB] [off] Capture [off]
  Front Right: Playback 0 [0%] [-34.50dB] [off] Capture [off]
Simple mixer control 'Mono Output Select',0
  Capabilities: enum
  Items: 'Mix' 'Mic'
  Item0: 'Mix'
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch cswitch-joined
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 15
  Front Left: Capture 0 [0%] [0.00dB] [on]
  Front Right: Capture 0 [0%] [0.00dB] [on]
Simple mixer control 'Mix',0
  Capabilities: cswitch cswitch-exclusive
  Capture exclusive group: 0
  Capture channels: Front Left - Front Right
  Front Left: Capture [off]
  Front Right: Capture [off]
Simple mixer control 'Mix Mono',0
  Capabilities: cswitch cswitch-exclusive
  Capture exclusive group: 0
  Capture channels: Front Left - Front Right
  Front Left: Capture [off]
  Front Right: Capture [off]
Simple mixer control 'External Amplifier',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]

sudo lspci -nnvv
00:00.0 Host bridge [0600]: Intel Corporation 82845G/GL[Brookdale-G]/GE/PE DRAM Controller/Host-Hub Interface [8086:2560] (rev 01)
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort+ >SERR- <PERR-
        Latency: 0
        Region 0: Memory at d0000000 (32-bit, prefetchable) [size=128M]
        Capabilities: [e4] Vendor Specific Information

00:02.0 VGA compatible controller [0300]: Intel Corporation 82845G/GL[Brookdale-G]/GE Chipset Integrated Graphics Device [8086:2562] (rev 01) (prog-if 00 [VGA])
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0
        Interrupt: pin A routed to IRQ 9
        Region 0: Memory at d8000000 (32-bit, prefetchable) [size=128M]
        Region 1: Memory at e5000000 (32-bit, non-prefetchable) [size=512K]
        Capabilities: [d0] Power Management version 1
                Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 PME-Enable- DSel=0 DScale=0 PME-

00:1d.0 USB Controller [0c03]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #1 [8086:24c2] (rev 01) (prog-if 00 [UHCI])
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0
        Interrupt: pin A routed to IRQ 16
        Region 4: I/O ports at d800 [size=32]

00:1d.1 USB Controller [0c03]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2 [8086:24c4] (rev 01) (prog-if 00 [UHCI])
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0
        Interrupt: pin B routed to IRQ 17
        Region 4: I/O ports at d000 [size=32]

00:1d.2 USB Controller [0c03]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #3 [8086:24c7] (rev 01) (prog-if 00 [UHCI])
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O+ Mem- BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0
        Interrupt: pin C routed to IRQ 18
        Region 4: I/O ports at d400 [size=32]

00:1d.7 USB Controller [0c03]: Intel Corporation 82801DB/DBM (ICH4/ICH4-M) USB2 EHCI Controller [8086:24cd] (rev 01) (prog-if 20 [EHCI])
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0
        Interrupt: pin D routed to IRQ 19
        Region 0: Memory at e5080000 (32-bit, non-prefetchable) [size=1K]
        Capabilities: [50] Power Management version 2
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
                Status: D0 PME-Enable- DSel=0 DScale=0 PME-

00:1e.0 PCI bridge [0604]: Intel Corporation 82801 PCI Bridge [8086:244e] (rev 81) (prog-if 00 [Normal decode])
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR+
        Latency: 0
        Bus: primary=00, secondary=01, subordinate=01, sec-latency=32
        I/O behind bridge: 0000c000-0000cfff
        Memory behind bridge: e0000000-e3ffffff
        Prefetchable memory behind bridge: e4000000-e4ffffff
        Secondary status: 66MHz- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort+ <SERR- <PERR-
        BridgeCtl: Parity- SERR+ NoISA+ VGA- MAbort- >Reset- FastB2B-

00:1f.0 ISA bridge [0601]: Intel Corporation 82801DB/DBL (ICH4/ICH4-L) LPC Interface Bridge [8086:24c0] (rev 01)
        Control: I/O+ Mem+ BusMaster+ SpecCycle+ MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0

00:1f.1 IDE interface [0101]: Intel Corporation 82801DB (ICH4) IDE Controller [8086:24cb] (rev 01) (prog-if 8a [Master SecP PriP])
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0
        Interrupt: pin A routed to IRQ 18
        Region 0: I/O ports at 01f0 [size=8]
        Region 1: I/O ports at 03f4 [size=1]
        Region 2: I/O ports at 0170 [size=8]
        Region 3: I/O ports at 0374 [size=1]
        Region 4: I/O ports at f000 [size=16]
        Region 5: Memory at 40000000 (32-bit, non-prefetchable) [size=1K]

00:1f.3 SMBus [0c05]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) SMBus Controller [8086:24c3] (rev 01)
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:000e]
        Control: I/O+ Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Interrupt: pin B routed to IRQ 11
        Region 4: I/O ports at 0500 [size=32]

00:1f.5 Multimedia audio controller [0401]: Intel Corporation 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) AC'97 Audio Controller [8086:24c5] (rev 01)
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:001b]
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 0
        Interrupt: pin B routed to IRQ 21
        Region 0: I/O ports at e000 [size=256]
        Region 1: I/O ports at e400 [size=64]
        Region 2: Memory at e5081000 (32-bit, non-prefetchable) [size=512]
        Region 3: Memory at e5082000 (32-bit, non-prefetchable) [size=256]
        Capabilities: [50] Power Management version 2
                Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+)
                Status: D0 PME-Enable- DSel=0 DScale=0 PME-

01:00.0 VGA compatible controller [0300]: Matrox Graphics, Inc. MGA G200 [102b:0520] (rev 01) (prog-if 00 [VGA])
        Subsystem: Matrox Graphics, Inc. Millennium G200 SD [102b:ff03]
        Control: I/O- Mem- BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Interrupt: pin A routed to IRQ 9
        Region 0: Memory at e4000000 (32-bit, prefetchable) [disabled] [size=16M]
        Region 1: Memory at e0000000 (32-bit, non-prefetchable) [disabled] [size=16K]
        Region 2: Memory at e1000000 (32-bit, non-prefetchable) [disabled] [size=8M]
        [virtual] Expansion ROM at e0010000 [disabled] [size=64K]
        Capabilities: [dc] Power Management version 1
                Flags: PMEClk- DSI+ D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
                Status: D0 PME-Enable- DSel=0 DScale=0 PME-

01:08.0 Ethernet controller [0200]: Intel Corporation 82801DB PRO/100 VE (CNR) Ethernet Controller [8086:103a] (rev 81)
        Subsystem: Acer Incorporated [ALI] Unknown device [1025:001b]
        Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B-
        Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR-
        Latency: 32 (2000ns min, 14000ns max), Cache Line Size: 32 bytes
        Interrupt: pin A routed to IRQ 20
        Region 0: Memory at e3000000 (32-bit, non-prefetchable) [size=4K]
        Region 1: I/O ports at c000 [size=64]
        Capabilities: [dc] Power Management version 2
                Flags: PMEClk- DSI+ D1+ D2+ AuxCurrent=0mA PME(D0+,D1+,D2+,D3hot+,D3cold+)
                Status: D0 PME-Enable- DSel=0 DScale=2 PME-

asoundconf list
Names of available sound cards:
I82801DBICH4
UART

cat /etc/asound.conf ~/.asoundrc*
cat: /etc/asound.conf: No such file or directory
cat: /home/craigus/.asoundrc*: No such file or directory

cat /proc/interrupts
           CPU0       
  0:        164   IO-APIC-edge      timer
  1:       1098   IO-APIC-edge      i8042
  6:          2   IO-APIC-edge      floppy
  7:          0   IO-APIC-edge      parport0
  8:          3   IO-APIC-edge      rtc
  9:          1   IO-APIC-fasteoi   acpi
 10:          0   IO-APIC-edge      MPU401 UART
 12:      86463   IO-APIC-edge      i8042
 14:      66459   IO-APIC-edge      libata
 15:      27816   IO-APIC-edge      libata
 16:          0   IO-APIC-fasteoi   uhci_hcd:usb1
 17:          0   IO-APIC-fasteoi   uhci_hcd:usb2
 18:          0   IO-APIC-fasteoi   uhci_hcd:usb3
 19:       4978   IO-APIC-fasteoi   ehci_hcd:usb4
 20:      81005   IO-APIC-fasteoi   eth0
 21:        388   IO-APIC-fasteoi   Intel 82801DB-ICH4
NMI:          0 
LOC:     539462 
ERR:          0
MIS:          0

dmsg attached.