Firefox sucks…(???)

Hi,
🙂
First of all i m sorry about topic cuz i already know it is the “BEST BROWSER” i ve ever seen and it is already my default browser at home and at work computers that i got but… now i have a problem and would like to learn if anybody else face that problem. Today firefox started to suck(haha) my whole physical and virtual memory. Computer slow down and when i check task manager out i realised firefox got 600 MB of mem usage(?) i stoped and restart firefox and it was seeming allright but after few hours again it get huge! Current computer is a XP SP2 and got no late changes about software and hardware. And opinion d be welcome…