I've tried Firefox a number of times and had problems. I've never had issues with IE, but I've installed Chrome and I like it. I just don't know my way around it well enough and it frustrates me, so I go back to IE.
I expect I'll ultimately end up using Chrome, it's nice and clean. I just need to have patience to suffer the learning curve or watch a short tutorial.
I've tried to get beside Safari and it just looks too much like iTunes and I hate iTunes with an unbridled passion.