Imovie Will Not Open At Optimun Screen Size


I have a powerbook g4.. running osx 10.3.9..

A few months ago my iMovie pogram started giving me a popup with the following error:

"To use iMovie your screen size must be set to at least 1024x768"

Then the app does not open (it just goes away after I clickthe popup)..

Someone at the apple store suggested I load iLife.. which I did.. with no change..

It will open if I change the screen size to 1024x768.. but I have at least two "better" settings (1024x768 stretched and 1152x720).. It will not open with "anything" but 1024x768.