I like Firefox, and any tables that show up with strange borders are probably using tags that only IE knows. That's not Firefox's problem, it's bad HTML.
The problem I am having is that I am getting serious lag (delays) every time I try to do something, like clicking Submit. I don't have a seriously fast machine, but I should think any browser would work reasonably fast on any but the most ancient of boxes. It's more than a little frustrating.
The strange thing is that seems that if the button has current focus, it will click immediately. But when it doesn't, it takes almost a full second to get focus before it depresses. I might be inclined to blame Windows XP, but at the moment my resources are 97% free, and I don't have this problem in other programs (including IE).