I tried to install quake live and ran into this problem. I couldn't find a solution to this issue on the forum so I thought I'd post my solution here in case others are having the same problems.
I am using firefox version 10.0.2 with the proprietary flash plugin along with openjdk.
Linux thomas-desktop 3.2.9-1-ARCH #1 SMP PREEMPT Thu Mar 1 09:31:13 CET 2012 x86_64 Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz GenuineIntel GNU/Linux
My solution was to delete the folder ~/.mozilla and then running firefox again. WARNING: This WILL reset your firefox to vanilla state, removing all favourites, cache, config, extensions and plugins I believe.
Kind of hurts, but at least it worked for me