I'm not sure if it is 4.2 or firefox but, often (as in sometimes every 20 minutes or so) while browsing the whole system locks up. The mouse still moves the cursor, but firefox will not respond, nor will KDE, keyboard or anything. Only restart option is a quick plug out and restart.
I'm using 11.1 and KDE4.2 on a Thinkpad r60e, I have never had problems before with 10.3, 11 or KDE 3.5.
Any ideas, or of log printouts which may help solve this very annoying problem?