Regarding the Firefox/IE thing, it in fact be related to plugins that use DirectX - specifically anything that creates a container process like Silverlight and Flash. Unfortunately this means that lots of web pages can cause slow-downs because of their stupid flash adds. The upshot is that it -appears- to also be related to the 3gb ceiling; I have not yet tested this by jumping into a 64bit browser, however. I do not use IE, and Firefox I believe is still 32bit only. I would be interested to know if anyone else has experienced this specific issue, and has the means to test it.