I believe this is a common issue with that player. Have you tried any of the other ones?
(I'm not entirely sure, a search would probably yield some results though.
)
I do know however, that you will probably need to reencode the videos to 8 frames or so a second
(see PocketDVD
).
That's probably not too helpful though if you're having lockups... but I thought I'd give you what I know.
Good luck.