Unfortunately, the site was created using the Microsoft Office HTML converter with VML enabled. This creates pages that works well in IE but poorly in Firefox. There isn't much that can be done about this from the end user's perspective. The site author would need to regenerate the pages with VML disabled and compatibility set to IE6 to get anywhere close to a site that works well in Firefox.

I've created a new practice website testing .css styles. Everything works fine in IE9 but I normally prefer Firefox. Current version of Firefox on my system is 7.0.1. Operating System is Windows 7. All updates installed. Problem is that with a horizontal menu bar (as a footer) Firefox recognizes some links but not all. Also have a vertical menu bar and all links are recognized without problem. The horizontal menu bar links are separated by a vertical bar (which I thought might be the problem, but it's not); some links are single words, some links are multiple words. Example page http://www.mullinsimagination.com/practice/index_mintl.html. There does not seem to be any relation whether a link is a single word or multiple words. Footer is located within two levels of <div> tags rather than using a <table>. I've made changes to everything I can think of but still not difference. Also verified code with validator.w3.org/check and all pages passed. Character set is UTF-8. Hope someone has a solution.

The problem is the height:500px of the #text DIV that covers the #footer DIV that you give the same value as the height of the image, but it starts lower and also has margins.
If you remove that height property then it should work or you need to subtract the top and margin values of that DIV from the height, but that will require constant attention if anything changes.

Try minimizing the use of the position property. You can make the large photo the background image of <div id="img1">. You can use the overflow property to control what happens if the text is too long. Then you really don't need to position the contents or worry about their height. Make sense?

I am having this problem with major websites (NY Times, Washington Post, Yahoo, USAA, Rotten Tomatoes, IMDB) so it would seem the problem is something for Firefox to fix. Most websites use horizontal menu bars, but Firefox has rendered them useless. Do I have to change browsers?

@sophos123, if your menus toward the top of most or all pages stopped working, it could be the problem in this recent thread which points to either a Yahoo or Babylon add-on as causing this problem:

"i can't click the upper icon on any websites"

Does that help?