I did this recently but I created a 768x576 graphic with my logo on it, in the bottom righthand corner. I saved it as a TIFF with a black background. I then put it on a video track above the video track and stretched it the entire length of the production to stop copying. I then used one of the keying effects to knock out the black background and rendered it. The black BG is now gone and the logo is displayed in the bottom righthand corner. It's just another variation of what was said before.

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