audio broken with modules upgrade on intel ICH8 Family HD Audio Controller

[absinthetized]

Binary package hint: linux-ubuntu-modules-2.6.24-23-generic

I'm currently running a downgraded version of the 2.6.24 kernel stack on my ubuntu 8.04lts x86_64. namely, I've hold the following packages to version 2.4.24-22:

utente@laptop:~$ aptitude search ~nlinux~n2.6.24-22~i
ih linux-headers-2.6.24-22 - Header files related to Linux kernel version 2.6.24
ih linux-headers-2.6.24-22-generic - Linux kernel headers for version 2.6.24 on x86/x86_64
ihA linux-image-2.6.24-22-generic - Linux kernel image for version 2.6.24 on x86/x86_64
ih linux-restricted-modules-2.6.24-22-generic - Non-free Linux 2.6.24 modules on x86/x86_64
ih linux-ubuntu-modules-2.6.24-22-generic - Ubuntu supplied Linux modules for version 2.6.24 on x86/x86_64

this is the only solution I've found in order to avoid audio issues originated _after_ the 2.6.24-23 modules upgrade. with 2.6.24-23 I'm able to listen to start/stop sounds on my box but all streaming sound is now muted (e.g. internet streaming or skype calls). I've discovered this issue now because I'm not used to enable audio on my laptop unless a skype conference is scheduled!

this is my lspci:
utente@laptop:~$ lspci
00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 03)
00:01.0 PCI bridge: Intel Corporation Mobile PM965/GM965/GL960 PCI Express Root Port (rev 03)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #4 (rev 03)
00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 03)
00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 03)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 03)
00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 03)
00:1c.2 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 3 (rev 03)
00:1c.3 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 4 (rev 03)
00:1c.4 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 5 (rev 03)
00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 03)
00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 03)
00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 03)
00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev f3)
00:1f.0 ISA bridge: Intel Corporation 82801HEM (ICH8M) LPC Interface Controller (rev 03)
00:1f.1 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03)
00:1f.2 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) SATA IDE Controller (rev 03)
00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus Controller (rev 03)
01:00.0 VGA compatible controller: nVidia Corporation GeForce 8400M G (rev a1)
02:00.0 Ethernet controller: Marvell Technology Group Ltd. 88E8056 PCI-E Gigabit Ethernet Controller (rev 12)
03:00.0 SATA controller: JMicron Technologies, Inc. JMicron 20360/20363 AHCI Controller (rev 02)
04:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN Network Connection (rev 61)
05:00.0 Memory controller: Intel Corporation Turbo Memory Controller (rev 01)
08:01.0 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 05)
08:01.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 22)
08:01.2 System peripheral: Ricoh Co Ltd R5C592 Memory Stick Bus Host Adapter (rev 12)

while this is the detailed lspci (-vv) for the audio device:

00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 03)
 Subsystem: ASUSTeK Computer Inc. Unknown device 8284
 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, Cache Line Size: 32 bytes
 Interrupt: pin A routed to IRQ 21
 Region 0: Memory at f3ff8000 (64-bit, non-prefetchable) [size=16K]
 Capabilities: <access denied>

the ubuntu is a 8.04lts version updated via "aptitude update && aptitude dist-upgrade". the kernel stack is the only one downgraded series of debs. I've also some custom packages (skype static, ooo 3.0.x from launchpad and virtualbox from sun site).

Matteo