If your video is upsidedown when you play it or after you have converted it or burned it.
1. Be sure to uninstall any codec packs you have installed like Nimo codec pack or others. And only install the codecs you need and be sure to get the latest codecs also. Use avicodec to identify the video so you know what codecs to download.
2. If the first step didn’t help try install latest ffdshow, it is a great DivX/XviD codec filter. Try play the video and if it is still up side down go to the Start Menu->ffdshow->Configuration. Select under Miscellaneous in the menu to the left and select Flip video. Hit OK and try play the video.