Facebook/Firefox problem

I have a Macbook that I've had for maybe a year. No problems really yet, aside from a harddrive failing, which I replaced. Recently, Facebook has been consuming all my memory when I someone messages me on FB chat. For 10-20 seconds, it'll just stop, videos will stop playing, typing will halt, it'll just come to a stop, then I'll get the message, and everything will continue. This happens every time I get or send a message. I like FB chat and don't want to turn it off, but this is ridiculous. I can use memory-heavy programs like Final Cut Pro just fine, but FB chat is screwing with me? I had Greasemonkey installed for Facebook and uninstalled it, assuming it might be the problem, but it wasn't. Any other ideas?

FB's ajax programming really isn't the most spectacularly clean I've seen. Do you have the same problem with FB chat in Safari?

I hate Safari with such a passion that I never even gave it a try.

It's worked just fine for months, maybe even a year, however long it's been since Facebook has HAD chat. It's just been the past week or so.

Trying Safari out now, runs just fine.