Sounds like you have something running in the background.
If you are sure you have nothing running, try the following.
Rename your AVi folder to AVI_back, update your video drivers, adjust the refresh rate, if that does not work try the acceleration setting for your video card.
If you are sure you have nothing running, try the following.
Rename your AVi folder to AVI_back, update your video drivers, adjust the refresh rate, if that does not work try the acceleration setting for your video card.