For me, Flash folded nearly every day – several times a day, in fact – on Firefox. And Firefox takes forever to load, too, which is the main reason why I don’t even use Firefox any more. Flash still crashes on Chrome, too, but not as often (though it seems to suck up memory like nothing else). At least Chrome starts more quickly.
I think the problem is more with Flash itself than with the browser. Maybe one of these days they’ll get it right.
For now, I try not to complain too much: it’s free, I didn’t have to develop it myself, and when it works I love it. I’m not going to bitch about it any more… right at the moment, anyway. Maybe next time it crashes or freezes my system.