You mean width-wise? I think the screen is set to 1100px wide. If you are using a netbook or a monitor with 1024x768 resolution, it wont fit. The reason I made it this wide was for the profiles. Any narrower and the videos wouldnt fit.
I'm assuming you're using a PC and not a Mac... If you're using Windows XP, go to your desktop and right click in the empty space. Select "properties" and try to find out what resolution you're using. If you're using Vista or Windows 7, right click in the empty space and click on "screen resolution".
What resolution is set? If it is 1024x768, can you slide it over to make the resolution bigger?