Issue opening apps when firefox open despite enough memory

I’ve been getting a weird issue where if I have firefox (3.6) open, I frequently cannot open other apps or even dolphin until I force quit firefox. However, when I look at “top” or sysinfo, it appears I have enough memory. This has been happening since about 1 month or so after I installed openSUSE 11.2 and has been getting progressively worse.

Sometimes when I try to open dolphin, it does nothing. If I then force quit firefox, dolphin suddenly opens up. And sometimes dolphin or other apps will just hang and I have to force quit them or quite firefox.

Right now, sysinfo says:

Total memory (RAM): 1.4 GiB
Free memory: 541.6 MiB (+ 506.1 MiB Caches)
Free swap: 2.0 GiB

But I’ve seen Free Memory listed as low as 27MB, but I’ve NEVER seen Free Swap be less than 2GB (NEVER).

Firefox (listed in “top”) has a 5.6% share of the CPU and a 7% share of the MEM. I’ve seen it higher but never anything insane.

openSUSE 11.2
KDE 4.3.4
Linux i686
AMD Sempron™ Processor 3100+ 1.8 GHZ
nVIDIA G98 GForce 8400 GS with nvidia driver

Any ideas why this is occurring?

Clear info, cheers.

It’s not memory, your swap is untouched, there’s 500 MB free.
Start FF from a terminal window, watch the output and see if you see any errors or warnings. If so, copy and paste them here, please.

Running from command line:

(firefox-bin:2260): Gdk-WARNING **: XID collision, trouble ahead

Also, when I quit firefox (after starting from icon on the taskbar, it went to 95% and then 98% usage of the CPU and just hung there (for well over a minute until I finally force quit it). After I post this message, I’ll quit this command-line-started firefox and let you know what happens.

UPDATE: Ok, when I quit from the command line it also went to 95-98% CPU BUT only for about 5-7 seconds and then it quit. Whereas the one started from an icon on the taskbar never quits.

Not sure if the Firefox never quitting has anything to do with the issue when trying to open other apps and dolphin though.