I'm trying to make a video with different clips and audio, but when I render it, the screen is blank and only the audio plays.

I've noticed that the video also doesn't show when I have the preview mode set to good or best, yet it does when it is set to preview or draft. I've never had this problem before until today.

The clips I am using are AVI files which I've created using AVS Video Editor. Could that be the problem? These AVI files all play fine using Media Player and RealPlayer, but not with QuickTime Player.

I'm really lost as to why this has happened!