it's usually that your codecs aren't installed propperly, if you have FFD show there is a quick fix option that will allow you to flip the video back. I would recommend looking at your codecs... a sure fix is: deinstall EVERY CODEC then install ffdshow (without xvid support!) then install latest (stable) xvid (www.koepi.org) and set it to be the codec for all FourCC's. This always worked for me so you might want to try it to. Codec packs are usually full of shit you don't need