I know the Liteon does not support 2 or more B frames with packed bit streams, it drops the frame and causes regular stutter. It does support 1 B frame with packed bit stream though.
I think you may have to find a program to unpack the bitstream and make a new file, its pritty quick as it does not re-encode the file.
I play alot of DivX files on my 5055GDL+ as I am slowly converting my DVD's into DivX using 1 B frame encodes.
To check your AVI files, download a program called GSpot from Doom9.org. Make sure you get the beta version as that reports Packed bitstreams, QPAL and GCM.