Working fine for months, now F17 only boots into Gnome Fallback mode

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http://forums.fedoraforum.org – I've tried a new user account, booting from older kernels, reinstalled nvidia driver, and checked the xorg conf files. Don't know what else to do? I had everything setup exactly as I liked and then out of the blue it refuses to load gnome shell. I am on thinkpad t61 with nvidia card. Please advise. (HowTos)