Menu shrinks in Internet Explorer

I don’t know what is happening with my site in Internet Explorer. It loads perfectly fine, but when you move the mouse over the menu it shrinks to a tiny text menu. It only happens in Internet Explorer.

I tried deactivating all the plug-ins to see if that was the problem, and it is not. I think it is a CSS issue. But I’m not even sure what to look for.

Here is a link for my site, so you can understand am talking about.
http://www.hunterdonbrewing.com/

I am sure all I need to do is add Internet Explorer fix to the CSS, but I don’t even know what attribute is causing this.

Thanks for all your help