I think I've zapped a PRAM about twice in my life. I haven't kept up with this stuff... Ya got me. :-)

I doubt that browser extensions are the issue. It's running less than I normally run - e.g. TabMixPlus, AdblockPlus, FlashBlock are about the only ones that have been installed (other than the usuals).

It's still happy at the moment - still only 480 MB of RAM used.

My guess is that there was some old garbage in the FF cache that was getting reloaded and grabbing memory and not freeing it properly. Yes, FF does have memory leaks, but this was really extreme.

I'm not willing to stick my neck out and say it's fixed, but it's looking good so far.

Thanks.

Cheers,
Scott.