Same issue here on 10.04. After booting the kernel log is spammed with:

[  544.968189] dvb-usb: bulk message failed: -110 (4/0)
[  544.968198] cxusb: i2c read failed

... and the system load sits on 1.00 consistently (Single core single CPU system) despite nothing showing in top and the cpu being listed as 99.3% idle. vmstat doesn't show any oddly high interrupt rates and there system is not swapping.

It did NOT occur on 9.04, so it seems to be it might be some sort of regression. I have yet to reboot with the 9.04 kernel to see if that makes any difference, though. I also have two cards, a DViCO Fusion HDTV Dual Digital 4 and a LeadTek DTV2000H.

Adding the following line to a file in /etc/modprobe.d did not affect the issue:
options dvb-core dvb_powerdown_on_sleep=0

lsusb:
Bus 006 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 002: ID 1241:f728 Belkin 
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 003: ID 0fe9:db78 DVICO FusionHDTV DVB-T Dual Digital 4 (ZL10353+xc2028/xc3028) (initialized)
Bus 002 Device 002: ID 0fe9:db78 DVICO FusionHDTV DVB-T Dual Digital 4 (ZL10353+xc2028/xc3028) (initialized)
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 152d:2329 JMicron Technology Corp. / JMicron USA Technology Corp. 
Bus 001 Device 002: ID 152d:2329 JMicron Technology Corp. / JMicron USA Technology Corp. 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lspci -v:
00:00.0 Host bridge: nVidia Corporation nForce3 250Gb Host Bridge (rev a1)
	Flags: bus master, 66MHz, fast devsel, latency 0
	Memory at f0000000 (32-bit, prefetchable) [size=32M]
	Capabilities: <access denied>
	Kernel driver in use: agpgart-amd64
	Kernel modules: amd64-agp

00:01.0 ISA bridge: nVidia Corporation nForce3 250Gb LPC Bridge (rev a2)
	Subsystem: Giga-byte Technology Device 0c11
	Flags: bus master, 66MHz, fast devsel, latency 0

00:01.1 SMBus: nVidia Corporation nForce 250Gb PCI System Management (rev a1)
	Subsystem: Giga-byte Technology Device 0c11
	Flags: 66MHz, fast devsel, IRQ 10
	I/O ports at e400 [size=32]
	I/O ports at 1c00 [size=64]
	I/O ports at 2000 [size=64]
	Capabilities: <access denied>
	Kernel driver in use: nForce2_smbus
	Kernel modules: i2c-nforce2

00:02.0 USB Controller: nVidia Corporation CK8S USB Controller (rev a1) (prog-if 10)
	Subsystem: Giga-byte Technology Device 5004
	Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 20
	Memory at fa003000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: ohci_hcd

00:02.1 USB Controller: nVidia Corporation CK8S USB Controller (rev a1) (prog-if 10)
	Subsystem: Giga-byte Technology Device 5004
	Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 22
	Memory at fa004000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: ohci_hcd

00:02.2 USB Controller: nVidia Corporation nForce3 EHCI USB 2.0 Controller (rev a2) (prog-if 20)
	Subsystem: Giga-byte Technology Device 5004
	Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 21
	Memory at fa005000 (32-bit, non-prefetchable) [size=256]
	Capabilities: <access denied>
	Kernel driver in use: ehci_hcd

00:06.0 Multimedia audio controller: nVidia Corporation nForce3 250Gb AC'97 Audio Controller (rev a1)
	Subsystem: Giga-byte Technology Device a002
	Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 21
	I/O ports at bc00 [size=256]
	I/O ports at c000 [size=128]
	Memory at fa001000 (32-bit, non-prefetchable) [size=4K]
	Capabilities: <access denied>
	Kernel driver in use: Intel ICH
	Kernel modules: snd-intel8x0

00:08.0 IDE interface: nVidia Corporation CK8S Parallel ATA Controller (v2.5) (rev a2) (prog-if 8a [Master SecP PriP])
	Subsystem: Giga-byte Technology Device 5002
	Flags: bus master, 66MHz, fast devsel, latency 0
	[virtual] Memory at 000001f0 (32-bit, non-prefetchable) [disabled] [size=8]
	[virtual] Memory at 000003f0 (type 3, non-prefetchable) [disabled] [size=1]
	[virtual] Memory at 00000170 (32-bit, non-prefetchable) [disabled] [size=8]
	[virtual] Memory at 00000370 (type 3, non-prefetchable) [disabled] [size=1]
	I/O ports at f000 [size=16]
	Capabilities: <access denied>
	Kernel driver in use: pata_amd
	Kernel modules: pata_amd

00:0a.0 IDE interface: nVidia Corporation nForce3 Serial ATA Controller (rev a2) (prog-if 85 [Master SecO PriO])
	Subsystem: Giga-byte Technology Device b002
	Flags: bus master, 66MHz, fast devsel, latency 0, IRQ 22
	I/O ports at 09f0 [size=8]
	I/O ports at 0bf0 [size=4]
	I/O ports at 0970 [size=8]
	I/O ports at 0b70 [size=4]
	I/O ports at dc00 [size=16]
	I/O ports at e000 [size=128]
	Capabilities: <access denied>
	Kernel driver in use: sata_nv
	Kernel modules: sata_nv

00:0b.0 PCI bridge: nVidia Corporation nForce3 250Gb AGP Host to PCI Bridge (rev a2)
	Flags: bus master, 66MHz, medium devsel, latency 16
	Bus: primary=00, secondary=01, subordinate=01, sec-latency=10
	Memory behind bridge: f2000000-f4ffffff
	Prefetchable memory behind bridge: e0000000-efffffff
	Kernel modules: shpchp

00:0e.0 PCI bridge: nVidia Corporation nForce3 250Gb PCI-to-PCI Bridge (rev a2)
	Flags: bus master, 66MHz, fast devsel, latency 0
	Bus: primary=00, secondary=02, subordinate=02, sec-latency=128
	I/O behind bridge: 00009000-0000afff
	Memory behind bridge: f5000000-f9ffffff
	Prefetchable memory behind bridge: 40000000-400fffff
	Kernel modules: shpchp

00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
	Flags: fast devsel
	Capabilities: <access denied>

00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
	Flags: fast devsel

00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
	Flags: fast devsel

00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
	Flags: fast devsel
	Kernel driver in use: k8temp
	Kernel modules: k8temp

01:00.0 VGA compatible controller: nVidia Corporation NV44A [GeForce 6200] (rev a1)
	Subsystem: ASUSTeK Computer Inc. Device 81cd
	Flags: bus master, 66MHz, medium devsel, latency 248, IRQ 16
	Memory at f2000000 (32-bit, non-prefetchable) [size=16M]
	Memory at e0000000 (32-bit, prefetchable) [size=256M]
	Memory at f3000000 (32-bit, non-prefetchable) [size=16M]
	[virtual] Expansion ROM at f4000000 [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: nvidia
	Kernel modules: nvidia-current, nvidiafb, nouveau

02:08.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 61)
	Subsystem: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller
	Flags: bus master, medium devsel, latency 32, IRQ 16
	I/O ports at 9000 [size=32]
	Capabilities: <access denied>
	Kernel driver in use: uhci_hcd

02:08.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 61)
	Subsystem: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller
	Flags: bus master, medium devsel, latency 32, IRQ 17
	I/O ports at 9400 [size=32]
	Capabilities: <access denied>
	Kernel driver in use: uhci_hcd

02:08.2 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 63) (prog-if 20)
	Subsystem: VIA Technologies, Inc. USB 2.0
	Flags: bus master, medium devsel, latency 32, IRQ 18
	Memory at f9004000 (32-bit, non-prefetchable) [size=256]
	Capabilities: <access denied>
	Kernel driver in use: ehci_hcd

02:0a.0 Multimedia video controller: Conexant Systems, Inc. CX23880/1/2/3 PCI Video and Audio Decoder (rev 05)
	Subsystem: LeadTek Research Inc. Device 6f2b
	Flags: bus master, medium devsel, latency 32, IRQ 18
	Memory at f5000000 (32-bit, non-prefetchable) [size=16M]
	Capabilities: <access denied>
	Kernel driver in use: cx8800
	Kernel modules: cx8800

02:0a.1 Multimedia controller: Conexant Systems, Inc. CX23880/1/2/3 PCI Video and Audio Decoder [Audio Port] (rev 05)
	Subsystem: LeadTek Research Inc. Device 6f2b
	Flags: bus master, medium devsel, latency 32, IRQ 18
	Memory at f6000000 (32-bit, non-prefetchable) [size=16M]
	Capabilities: <access denied>
	Kernel driver in use: cx88_audio
	Kernel modules: cx88-alsa

02:0a.2 Multimedia controller: Conexant Systems, Inc. CX23880/1/2/3 PCI Video and Audio Decoder [MPEG Port] (rev 05)
	Subsystem: LeadTek Research Inc. Device 6f2b
	Flags: bus master, medium devsel, latency 32, IRQ 18
	Memory at f7000000 (32-bit, non-prefetchable) [size=16M]
	Capabilities: <access denied>
	Kernel driver in use: cx88-mpeg driver manager
	Kernel modules: cx8802

02:0b.0 Ethernet controller: Marvell Technology Group Ltd. 88E8001 Gigabit Ethernet Controller (rev 13)
	Subsystem: Giga-byte Technology Device e000
	Flags: bus master, 66MHz, medium devsel, latency 64, IRQ 19
	Memory at f9000000 (32-bit, non-prefetchable) [size=16K]
	I/O ports at 9800 [size=256]
	[virtual] Expansion ROM at 40080000 [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: skge
	Kernel modules: skge

02:0d.0 Mass storage controller: Silicon Image, Inc. SiI 3512 [SATALink/SATARaid] Serial ATA Controller (rev 01)
	Subsystem: Silicon Image, Inc. SiI 3512 [SATALink/SATARaid] Serial ATA Controller
	Flags: bus master, 66MHz, medium devsel, latency 32, IRQ 17
	I/O ports at 9c00 [size=8]
	I/O ports at a000 [size=4]
	I/O ports at a400 [size=8]
	I/O ports at a800 [size=4]
	I/O ports at ac00 [size=16]
	Memory at f9005000 (32-bit, non-prefetchable) [size=512]
	[virtual] Expansion ROM at 40000000 [disabled] [size=512K]
	Capabilities: <access denied>
	Kernel driver in use: sata_sil
	Kernel modules: sata_sil