I recently completed a video for a History project.

The video contains a large number of overlay effects such as gun flares. The first overlay that is encountered in the video, however, is a picture with a transparent background. The picture itself is Black Text.

As soon as Vegas attempts to render the first overlay, it displays a series of black, white, and lined frames, (As well as the original video frames from time to time) throughout the rest of the video.

All of the gun flare effects are under a 'Screen' overlay whereas the picture overlay is 'Source Alpha'.

Here are some pictures of the different images that show throughout the second half of the video:

http://dl.dropbox.com/u/57398252/F1.png
http://dl.dropbox.com/u/57398252/F3.png
http://dl.dropbox.com/u/57398252/F2.png

There are also completely white and black frames interlaced, of which I didn't bother to screenshot.