You might take a look at this in Firefox. The horizontal navigation wraps to the next line. Part of a border appears on the left, and the Google Ads are overlapping the right edge. Could be that something larger is out of whack, causing all these little problems.
You do have some coding errors
that need to be addressed. Stating a DOCTYPE will help immensely.
* My screen resolution is set at 1680x1050
* I'm accessing your site through a T1 line
* I'm probably viewing it using Firefox (unless browser is specified)