I just got the following in dmesg a few minutes after booting my
notebook which was idle at the time this occurred.  This was with
2.6.25-rc6 but I've seen the same with 2.6.22 (see the attached
dmesg from 2.6.22).

irq 19: nobody cared (try booting with the "irqpoll" option)
Pid: 0, comm: swapper Not tainted 2.6.25-rc6-amd64 #1

Call Trace:
 <IRQ>  [<ffffffff80271c0b>] __report_bad_irq+0x38/0x7c
 [<ffffffff80271e51>] note_interrupt+0x202/0x249
 [<ffffffff8027274e>] handle_fasteoi_irq+0xab/0xd0
 [<ffffffff8020f82c>] do_IRQ+0x6e/0xda
 [<ffffffff8020c65d>] ret_from_intr+0x0/0x19
 <EOI>  [<ffffffff80221831>] ? native_irq_enable+0x6/0x7
 [<ffffffff88006330>] ? :processor:acpi_idle_enter_bm+0x2ab/0x325
 [<ffffffff803b5ef3>] ? menu_select+0x70/0x99
 [<ffffffff803b52e1>] ? cpuidle_idle_call+0x77/0xa6
 [<ffffffff803b526a>] ? cpuidle_idle_call+0x0/0xa6
 [<ffffffff8020b187>] ? cpu_idle+0xb1/0xdb
 [<ffffffff8042ea16>] ? rest_init+0x5a/0x5c

handlers:
[<ffffffff8806f0f5>] (irq_handler+0x0/0x207 [firewire_ohci])
Disabling IRQ #19


tbm@loric-alpo:~$ lspci
00:00.0 Host bridge: Intel Corporation Mobile PM965/GM965/GL960 Memory Controller Hub (rev 0c)
00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)
00:02.1 Display controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (rev 0c)
00:19.0 Ethernet controller: Intel Corporation 82566MM Gigabit Network Connection (rev 03)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Contoller #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)
00:1d.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 82801HBM (ICH8M-E) LPC Interface Controller (rev 03)
00:1f.1 IDE interface: Intel Corporation 82801HBM/HEM (ICH8M/ICH8M-E) IDE Controller (rev 03)
02:06.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev ba)
02:06.1 FireWire (IEEE 1394): Ricoh Co Ltd R5C832 IEEE 1394 Controller (rev 04)
02:06.2 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 21)
02:06.3 System peripheral: Ricoh Co Ltd R5C843 MMC Host Controller (rev 11)
10:00.0 Network controller: Intel Corporation PRO/Wireless 4965 AG or AGN Network Connection (rev 61)

-- 
Martin Michlmayr
http://www.cyrius.com/