[PD] Trying to figure out why pix_video isn't working

[jim]

For some reason pix_video isn't working for me. I've tried a few
different webcams, all of which work in other programs. I'm on a 64 bit
Linux Jaunty machine and using 
 
Pd version 0.42.4.
GEM: ver: 0.91.3 'tigital' 

I keep getting this error in the console when I select a camera using a
device message

VDIOCGCHAN: Invalid argument

Any thoughts how to track the problem down and get it working?
Thanks,

Jim