Firstly, they aren't likely to be divx these days
divx to dvd will be a reencode since mpeg4 requires downgrading to mpeg2, and hdtv mpeg4 can not be repacked to lower resolutioned mpeg4 without re-compression.
I think you need to re-encode. If you got a HDTV version with the high res, its probably too much for your player (its not very good
). If its a 350mb rip with the lower sub 720x resolution, i'm very surprised they don't work. They should since they are standard xvid.
I don't think they are advanced profile rips are they (use gspot to test for packed bitstream, etc.)? I'm pretty sure very few scene releases these days use standalone incompatible process of encoding.