I have a header menu created using a styled list, that is constrained by a header div.
The problem is that some computers render the text different sizes, which is a problem as all the butons are different sizes so the spacing is done by padding on the 'li a'.
On my PC it is Ok, on some PC's the menu ends up a bit short, but the bigest problem is on the Mac where the last itemgets shoved on to a new line.

Page CSS

I have had this problem before but only in headers and the like, where sizing wasn't critical. Here it's turned into a serious problem though.

Thanks for any help