I realise that you may not want to try another program, but with Auto Gordian Knot, it doesn't estimate file size so you may find it helpful making specific file sizes. It can also be made to use the Xvid or Divx 5 codec (To change this go to the 'Advanced Options' button) so you can some preference there as well.
Here is a little tutorial I wrote up for it. It says that it is for movies on the X50v but it also works on 320x240 screens;)
http://www.aximsite.com/boards/showt...829#post532829
Have Fun!
-Brad :approve: