Thank you guys for figuring this out and posting about it, I was going nuts! The exact same stuff happened here after the Marvell Update, random freezes, sometimes not even related to the internet (on the surface at least!) Unfortunately it happened to me right after I had been tryin some overclocking, and it was sort of acting as though I had corrupted some drivers on my hard drive, so I was bugging out, but lo and behold, Anandtech.com had the answer once again! Thanks a ton, and anybody reading this who recently updated their Marvell Yukon Ethernet drivers but aren't really convinced that this is the problem... try it, I was a little skeptical (mainly cause of freezing during programs that don't use the internet!) but as soon as I rolled back the drivers, all of the freezing stopped immediately. And if you have automatic updates from Microsoft, you may have been updated without knowing, right? I'm not sure about that, cause I update manually, but just a thought.