Standby and Hibernate stopped working

[dsigma6]

Vista Ultimate on a T23. Standby and hibernate worked fine, then I swapped in an XP hard drive for a relative to use, and then put the Vista drive back in. When I standby or hibernate, the screen goes to black with a white cursor, just like it would before, but that's where it stops. The standby light on the ThinkPad does not blink.

I have not changed any options regarding the sleep state, I have it set to hibernate when sharing media (which I'm not doing), and I'm all out of ideas. I didn't touch any BIOS sleep states.

Short of going back to XP, I'm clueless!