Breaks in Firefox Mac only?

I’m in the process of amending a website for a client. It’s almost done but unfortunately it appears broken in Firefox (Mac only!).

The main problem is the Hori Nav system that seems to have some padding on the gif corner image. You can also see an image behind a flash file on the right of the header.

The strange thing is that this only breaks in Firefox for the Mac.
The XHTML is vaildated, so I’m getting pretty stuck at the mo.

Please help if you can.

The link is here:

Looks the same in FF Mac to me as in other browsers. What should I be looking for?

You get the same effect in Firefox for the PC yesterday the page wasn’t fully functional today it is, I suspect it is the Flash animation of the women (above the horizontal navigation) that is not centrally aligned, or filling the width which is the problem?

It leaves a large black gap to the right of the Flash object. If I have time later I might look