Header Image in Widget is Partially Cut Off

Hi, I have created 3 widgets in the header so I can have a logo on the left and a header image in the center - the 3rd cell is empty.

But - in certain browsers, I can't tell if it's due to IE6 or smaller screensizes, the header image gets cut off on the right side.

How do I move the 3rd widget cell slightly to the right to avoid this problem?


Thanks!