Trouble with DivX audio/video sync...

I have been an avid user of DivX for a few years now, and I use it to encode files into DivX format to watch on my DivX certified DVD player. However, a few weeks ago, all of my files either didn't work, or the audio and video slid out of sync halfway through the episode or movie. Could this have anything to do with the DivX Pro update? And if so, how do I get back to my old DivX program? Also, I have checked for updates, and it says that I am up to date.