Seems to be a real problem though. Can't prove my assumption since I haven't bothered to research it. But I experience it as well. The good old trusty power button works a lot better. Even tried shut down after 1hr of no use into hibernation mode. Work great unless winamp is playing.. once ya boot back up shit hits the fan.

Maybe install the monitor drivers? Though experience has shown monitor drivers install dick all, expect the name of the monitor. :P Or make things look worse.
Could check for how any duplicates of power saving modes are in use, tends to happen from time to time. Could be a conflict.
No idea though.