A few months ago I was working on displaying a Flash movie at 100% width and height in a browser window. The biggest problem I ran into was that I wanted to make it so that the movie would scale (shrink/expand) as the user resized their browser window. The problem? In Mozilla/Gecko browsers, the Flash content always got chopped off below 200 pixels of height. I tested this in several browsers on Windows and OS X, and the problem was consistent across platforms with different Gecko browsers (Firefox, Netscape, Camino, etc.). But Safari and Internet Explorer didn’t have that problem.
Today I found an article which describes the CSS necessary to scale a movie to 100% width and height. I will try it out and see if it suffers from the same cutoff-below-200-pixels problem I ran into.