Cheese: "No camera found!"

[Detlef Lechner]

Hi,

lsusb recognizes my Web cam Logitec Quickcam E2500 (http://nopaste.debianforum.de/31734). Some days ago this web cam produced pictures and videos on Cheese and Linphone on this Karmic computer but last night Cheese reports: "No camera found!" 
At that time /var/log/messages outputs: 
http://nopaste.debianforum.de/31733.
'~$ lsmod' signifies that the modules v4l1_compat, vesafb, video and videodev are loaded.
/dev/video0 with (81,0) exists.

'~$ xawtv /dev/video0' produces (except for start messages) the repeating message: "libv4lconvert: Error compressing JPEG: unknown huffman code: 
0000ffff." The Huffman values sometimes (but rarely) differ from 000ffff.
I unplugged the USB camera plug and plugged it in the second USB receptacle. This made no difference.
How to troubleshoot?

Regards,
Detlef Lechner