.mov skipping?

[crank@got.net (i'll teach you to turn away.)]

	hey guys. i'm running the latest testing, but i've had this issue 
for months. i'm able to play movie files no problem: g/mplayer works 
beautifully for nearly everything. every so often, though, i have a .mov 
file that doesn't play video smoothly - the audio sounds fine, but the 
video skips so badly that it appears to be more like a series of still 
images that vaguely line up every 3-10 seconds with the audio. i don't 
know enough about video to figure out what it's missing, & google doesn't 
come up with anything similar. any help?

lish
crank@got.net