I'm using Slackware 14.0 since some time, having a wonderful experience which even superseded my great time with 13.37.
It came pre-installed with Firefox 15.0.1 if I'm not wrong, but I removed it and installed an older version 3.6.28 because on it would start slowing down as the uptime gets high. Like if I'm up for 3 days and start Firefox, after some good start it would crawl like a panda and choosing an opened tab would take 2 seconds, even with adblock and flash block plugins.
Firefox 3.6.28 didn't have this problem but some websites would simply refuse to work properly with an older version of FF.
Right now I'm on Firefox 10.0.9 ESR, which I installed myself but situation is pretty much the same. It's slow as compared to FF 4.0 in Slackware 13.37 or for the matter FF 8.0 which I had last on my 13.37 machine.
So the scenario is that rest of the system is doing great with a low load average and just fine memory consumption because there are minimal processes running but FF 10.0.9 ESR is taking up around 500 MB memory with 2 tabs opened, one is LQ and other is FB.
Is it like FF is getting older with each newer release or I'm doing it wrong?
Bit of info about machine and current uptime:-
cruise@pinguslack:~$ uname -a
Linux pinguslack 3.2.29-smp #2 SMP Mon Sep 17 13:16:43 CDT 2012 i686 Intel(R) Core(TM)2 Duo CPU T6400 @ 2.00GHz GenuineIntel GNU/Linu
22:13:57 up 6 days, 22:37, 6 users, load average: 0.55, 0.43, 0.34