Quicktime error...cannot open videos from "My Videos" folder. Help!

Hello. I'm running Windows XP SP2. I have lots of video files (Quicktime format..filmed via Panasonic digital camera) saved in the "My Videos" folder on my hard drive. I have always been able to open the folder, double-click the selected movie and watch the video open in it's own Quicktime window for play (and it has always played just fine). A few days ago things changed. When I double-click a selected clip the Quicktime window opens..but when I push PLAY I get this message: "QuickTime Player has encountered a problem and needs to close. We are sorry for the inconvenience." HOWEVER,..if I go to the desktop and launch Quicktime from the desktop icon I can browse for my video (through the Quicktime file menu), find it and it plays perfectly. I can also (once Quicktime has been launched from the desktop) minimize it, then proceed to search for videos in the "My Videos" folder as usual and play them with no problem. It's a minor unconvenience, but I sure miss just simply navigating to "My Videos" and firing up the clips from there. Any ideas? I uninstalled the re-installed Quicktime and that didn't help. Itunes seems to be working fine as well. Any help appreciated. Thanks.