>I notice the A.Menu:link, A.Menu:visited, and A.Menu:hover styles defined in 'stylesheet.css' used by IE do not appear in 'Netscape.css' used by Firefox. These appear to be the styles assigned to the hyperlinks in the left nav area of the main page. Maybe this has something to do with the problem.

Yes, correct, I just discovered that a few minutes ago. I think the general stylesheet should fit well for all browsers now. I'll do some testing on that.