Windows 7 compatibility issue?

Hi
I recently created an exe file from Flash which pulls in seperate swf files as and when required. The swf files have the images and audio embedded and dont pull anything else in. All works fine on Macs and Windows XP and Vista. Unfortunately we dont have Windows 7 yet - but our client does. The main exe loads and pulls in the files but only audio is 'visible' and plays fine but with no imagery. The images will display if he hits the esc key or a volume key (but apparently not with letters keys etc).

Does anybody know of this issue and a solution to it?