It looks like your wrapper is a little small to fit in the content. That's easily changed in the stylesheet.css file in your CSS folder.

Aside from just increasing the width, a VERY VALUABLE TOOL is the 'Inspect Element' add-on for FF. With it, you can dynamically break apart page elements. I'm sure I'm not the only one on this site who will tell you it's an invaluable tool to solve cross-browser compatibility issues.

I'm in the process of changed my funny tees website www.gafy.com which was originally defined for an 800x600 resolution to around 1000px. Just changing the mainwrapper width (in the CSS file) solved everything AND gave me tons more real-estate!

Whatever the solution...do yourself a favor and make sure you have Inspect Element add-on! You'll love it!

Good luck!