Cannot resume from StandBy

My computer developed an annoying new problem: When I try to resume from StandBy, it seems to start up, then goes back into Standby again, then tries to resume. Repeat ad infinitum.

Last night, I installed a Windows update (KB980182 - IE fix), updated the Realtek (network) driver (from Windows update), updated FileZilla, and updated Adobe Download Manager (actually, I think it uninstalled). None of these seem like likely culprits.

Should I try a system restore to see if that resolves the problem? Has anyone else seen this problem and figured out a way to solve it?

Yes - but more importantly they are the same as they were two days ago when resuming from standby worked perfectly.

FZ21Z - I ran a careful experiment and can report that absolutely nothing appears in the event log at the time of the failed resume. Does this imply that the issue has nothing to do with Windows, but rather is hardware related? If so, how could something like this start happening when no hardware or BIOS changes were made?

Turns out the problem was interesting - one (or two) of my four DIMMs went partially bad! The system would boot, but not resume from StandBy (as described below). Further evidence of the problem was that the memory was showing as being single channel instead of dual channel. When I swapped the DIMMs, the system would no longer boot. When I removed the bad one(s), the system would again resume from StandBy properly.