I love Firefox, too. Although it does have it's challenges. As xstr8guy pointed out, sites seem to fall apart in Firefox. But that's not Firefox's problem, the main problem is that, in their quest to take over the browser market, Microsoft's IE allowed for really sloppy HTML. If you didn't close a tag, IE would assume you wanted it closed. This pretty much assured that everything looked great in IE while Netscape Navigator seems to be a shoddy product not displaying websites properly.

So everyone jumped ship and moved over to IE. Now, a whole bunch of years later, we find that a lot of our sites are not looking so good when displayed in a strict W3C browser like Firefox.

Cheers
Dzinerbear