Comment 8 for bug 216310

I'm having similar/same problem. Firmware seems to have loaded successfully... product ID changes.

cjp@byzantium:~$ dmesg | egrep '(uvcvideo|5\-4)'
[ 28.535584] usb 5-4: new high speed USB device using ehci_hcd and address 3
[ 28.672008] usb 5-4: configuration #1 chosen from 1 choice
[ 41.023834] uvcvideo: iSight firmware: firmware successfully loaded.
[ 41.023844] uvcvideo: Found UVC 0.00 device <unnamed> (05ac:8300)
[ 41.023849] uvcvideo: No valid video chain found.
[ 41.023895] usbcore: registered new interface driver uvcvideo
[ 41.095860] usb 5-4: USB disconnect, address 3
[ 42.775095] usb 5-4: new high speed USB device using ehci_hcd and address 6
[ 42.908247] usb 5-4: configuration #1 chosen from 1 choice
[ 42.908503] uvcvideo: Found UVC 1.00 device Built-in iSight (05ac:8501)
[ 42.908525] uvcvideo: No valid video chain found.

uname -a:
Linux byzantium 2.6.24-16-generic #1 SMP Thu Apr 10 12:47:45 UTC 2008 x86_64 GNU/Linux