I think I have discovered a memory leak or incompatibility with Firefox 6.0 and Windows 7 64-bit. I keep having my computer seize up and auto-power-down (cold shut down, not a system reboot). I've memtested, scoured for virii and malware, etc.
Upon reflection, the crash ONLY happens when running Firefox.
So I'm running Iron... the non-Google copy of Chrome browser.