Here's what the MSDN Bugcheck Code Reference (
http://msdn.microsoft.com/en-us/library/windows/hardware/hh406232(v=vs.85).aspx) says for STOP 0x9F
For Parm 1 = 0x3 (Windows XP and later)
Param 2: The physical device object (PDO) of the stack
Param 3:The functional device object (FDO) of the stack. In Windows 7, this parameter points to the nt!TRIAGE_9F_POWER structure.
Param 4:The blocked IRP
CAUSE: A device object has been blocking an IRP for too long a time.
You report the issue appears after installing new drivers. I've seen reports of driver installation causing problems with other installed drivers. I encountered video problems after installing a new version of the Realtek Audio driver. For this reason, I now install and uninstall drivers from within Safe Mode. Safe Mode disables running drivers that may potentially interfere with your driver installations.
I suspect a driver installation may have corrupted the Power4Gear driver(s). Since Windows can provide everything in the way of power management that P4G provides, I would NOT reinstall it. It is one less thing to worry about.
G74SX-A1 - stock hardware - BIOS 202 - 2nd Monitor VISIO VF551XVT