A problem with Firefox

For a while I’ve noticed my computer running slower and slower for no apparent reason. Although I have a fairly old computer (Athlon 1.2GHz) it was running far slower than it should have been.

A (not so) quick look in task manager revealed a possible culprit - Firefox was running and taking up 80Mb of memory and it was increasing. Anybody any ideas what could cause a sudden and persistent memory leak in Firefox? The only extra I have installed is LiveHeaders. Until it’s fixed I’ve had to revert to IE.