Hello this has been written many times now, I’m sure, but just in case (I realized this only after 2 years of use).

For biger divx movies –For N800 - , this gives usually (tested from downloaded movies 4 out of 5 worked nicely, one has problems) nice quality without conversions, or bad frame drops:

mplayer -ao sdl –framedrop -vfm ffmpeg

This seems superioir IMO to -lavdopts skipframe=nonref:skiploopfilter=all -vfm ffmpeg, where the skipped frames are really bad, not to mention lowres=1.

In config:
ao=sdl
framedrop=yes
vfm=ffmpeg