I am facing the same problem. I am currently using AVI format and videos are playing.
I used format fatory for AVI conversion but after conversion from Mp4 to AVI, most of the videos didn't play then i used WinFF to convert from mp4 to AVI. Videos are playing but they are missing frames in video while playing it which spoil the mood of the song.
If you find some good software which convert EVERY MP4 to AVI (because in some softwares after conversion to AVI, some videos are playing and some are not) in HD Quality and without any flaws (missing frames or anything else) then please let me know too.