BT878 brooktree video card freezes ubuntu desktop
 

Hi I have a strange problem on ubuntu 10.04 and ubuntu 9.10,
the bttv card I was able to install and make it work by creating the file
/etc/modprobe.d/bttv.modprobe
and adding
options bttv card=77

Now I can see cameras via xawtv however it randomly freezes after some seconds, apparingly even earlier when the signal is disturbed.
Even easier it is if I launch motion, then it freezes as soon as motion starts.
By freeze I mean the picture on the monitor becomes fixed, no mouse, no keyboard and ssh or CTRL+ALT+DEL don't do anything, so completely stuck I have to pull the plug!
Also no logs because as soon as it freezes it writes nothing on the logs
Any Help?