I've used xvidcap some month ago, then after upgrade in sid (go to 1.1.7) i had a kind of codec error trying with about all codec and file format (flv, avi, xvid, asf), video seems normally recorded, but while watching him (with vlc or mplayer) video shows all green with big pixels and show just a little area of originally selected area.

Above you can see an example of a few second video of my desktop… normally it's black :)

http://rapidshare.com/files/300536281/test-0000.mpeg.html

here my xdpyinfo too
http://debian.pastebin.com/m578d4baa