Well rebuilding the desktop is a totally different issue.
Do you mean resetting the Power Manager? (The memory manager is part of the CPU, and is not user-accesible). Did you try holding the reset button for 10 seconds, with the machine off, instead of just briefly pressing it?
You didn't pdate your firmware and turn on the firmware security, did you? That would prevent the PRAM from resetting.
If all else fails, shut down, unplug the AC adapter, remove the battery, and let the machine sit there for overnight. That should be plenty of time for the backup battery to die, and reset the PRAM.
tooki