Hmmm.... wasn't getting image upside down something that happened long time ago with old movies when using old codecs? Doh... I don't remember now.
Be sure to install the latest divx5, xvid by Koepi and oggds.
In XVid decoder preferenced you have a box called "flip video", try changing that.
Are you using ffdshow? (ffdshow should also have something called "flip video" or something)
What the...
Why I'm writing this...
Use search!!!
http://forum.bsplayer.org/search.php
and write there
upside AND down
Lots of posts.
See here for example:
http://forum.bsplayer.org/viewtopic.php?p=15117#15117