Firefox 1.5/2 memory leaks

I was just accessing my home server (used to download/seed torrents and server files over my network, plus as an apache/mysql test server). I keep Firefox running most of the time minimised, with sites I use all of the time open in a selection of tabs for quick access. It is a very old 1.5 version. I've basically keep such an old version in use for site testing so I can make sure sites do look the same in 1.5, as they do in the current version. Anyway...

The system was running very slowly and everything was unresponsive and taking minutes to respond to mouse clicks. I looked in the Task Manager and my system resources were using 1.9GB (1GB physical ram + virtual memory), which is a lot and no wonder the system was acting so slowly. So I first closed Firefox and instantly the system resources dropped right down to less than 900MB. So FF was using over 1GB of system resources just to stay open with 6 sites open in tabs! Mad! Definitely the famous memory leak mentioned so much. I did still have uTorrent running in the background seeding a lot of torrents so that was always going to be eating up quite a lot, but closing FF instantly returned the system to being responsive and usage.

So the thing I'm now wondering, is if FF3 has fixed these memory leaks? They were obviously present in version 1.5 as I just witnessed, and widely reported as being a part of version 2. So are they all fixed in 3? I've been running FF3 tonight with the Task Manager open showing the Process list and so far the Firefox memory usage hasn't increased at all. If I did the same with FF2 I used to notice the memory usage was constantly increasing like a slow clock. So maybe it is finally fixed.

Lets hope so. :)

Now the delema. Do I install FF3 on my server? Or leave 1.5 on there for testing purposes? I think I might leave 1.5 on there and just install Opera for day to day usage! ;)