Are they in the right format? They'll have to be mpeg4 or H.264. There's a lot of iPod/iTunes info here (some video info too)
http://www.gnutellaforums.com/showthread.php?t=36230
For converting video I use 3GP converter. Lots of info here
http://www.gnutellaforums.com/showth...=&pagenumber=1