remove black line from powerpoint movie file playback

[Ronda]

I have a avi movie file embedded in a powerpoint file. Both the movie file
and the powerpoint fiel have a matching grey background. But when I play the
file in my slide show I get a black bar along the right size of the playback
window. If I try cropping the movie image file the black bar along the right
side disappears and I get on along the top and bottom of the playback window
instead.