Fun little thing. I reinstall FO3, and start a new game. After sitting through the obnoxious tutorial section of the game, I left the Vault for the Capital Wasteland, only to find myself moving an acting at 50% (rough guess) of normal speed. Not running any plugins, and tried this with both the basic launcher, and through FOSE. Apart from the tutorial levels, which ran just fine, it's all the same result - stuck in slo-mo.

Shouldn't be the hardware or drivers, as it was running just fine last time I had it installed with the same setup. Any ideas?

check for a joystick or game pad with anolog controls, happened in oblivion, it might here as well