I usually find Firefox grows in memory size the longer it runs. For me the fix is simple. I exit firefox and start it up again. It works for awhile until it grows again.
The screen saver will only aggravate the low memory issue. Try it with a simpler BLANK SCREEN saver or many none at all.
I have an older computer with Windows XP as the OS. I have a 1.10 Ghz Duron processor, but only 384 MB of RAM. For internet I only have dialup and use Juno as my ISP. I use Firefox 3 as my browser.
Whenever I first power up my computer it runs pretty smoothly. However, I've noticed that whenever I have Juno and Firefox up for very long, eventually my computer processing speed will slow to a crawl and stay that way until I reboot. Once I reboot, the processing speed is fine again, until the next time I've had Juno and Firefox up for a while. Also, the problem continues whether I'm connected to the internet or not, unless I reboot.
Here's some additional info: Many times when my system is at a crawl I notice that my CPU usage is very low, so it's not that the CPU is being overtaxed. I've also checked for spyware and viruses, and so far my anti-virus and anti-spyware programs have not found any problems.
I've noticed this issue seems to be aggravated whenever my screen saver has been up for a while. Also, whenever I'm having this problem I'll have a lot of instances of Firefox and/or Juno "not responding" (usually Firefox). They just seem to hang up and sit there for ever and ever, though the CPU doesn't appear to be doing anything.
Can anyone tell me what's causing this problem?