I found the best way to use Power Scheduler was to use it to wake up the computer (for recording) but leave Windows responsible for putting the computer into standby afterwards.
So for example, Windows is set to go into standby after 30 min, MP would wake the computer up, do the recording and 30 minutes after the recording has finished, it goes back to sleep. It works very well and does away with all the nonsensical stuff that you (and I) experienced when you let MP put the computer into standby.
For those worried about screen burn you can independently turn off you monitor in Windows Power Options. I set mine to 5 minutes.