I've seen this posted as a known bug in Premiere, but I haven't found a decent solution to it. Here's a screen cap of what it looks like:
Notice the pink verticle line on the right side of the frame. This happens when I'm exporting it out of the timeline to another format - it doesn't look like this in the timeline. I have done a few tests and it seems to only do this when:
A) it's fading from black or to black - cross-dissolving from one video to another doesn't do it
and
B) the output video is in widescreen 16:9
It doesn't happen when I'm creating an HD video and it doesn't happen when it's an SD video in "D1/DV NTSC (0.9091)" aspect.
Thoughts?