Files/Folders Sticking to Mouse Pointer - Not Releasing (Reset PRAM & Apple Hardware Test Fail to Run)

I've been having two issues with my Late 2008 MacBook Pro 15-inch - Running OS X 10.8.5 (Mountain Lion). Unable to Reset the PRAM and Run Apple Hardware Test (AHT).

On a random basis - File/Folder icons are Sticking to the Mouse Pointer - Not Releasing. I've done everything from trashing finder preferences, making sure Universal Access preferences are off, Restoring Defaults in the Energy Saver System Preferences, Resetting the System SMC. Another post mentioned that this is being caused by the Graphics Driver not working correctly - and mentioned to put the MBP to sleep, then wake it up, and the files/folders are no longer sticking to the mouse pointer. This works for me and released the sticking items in the Finder.

OK, Good this is a simple fix, BUT, what is really causing this issue, and how may it be fixed or repaired?

I also tried to Reset the PRAM and Run the Apple Hardware test (AHT), and these both fail to run on my MacBook Pro with OS X 10.8.5.

1) Resetting the PRAM:

Shut down the MBP, press the power button, and hold down at the same time <option><command>-P-R. The Reset PRAM process never starts up, but rather I receive the Padlock/Password Login which logs me into the Restore System Utilities. I'm unable to Reset the PRAM.

2) Apple Hardware Test (AHT):

Shut down the MBP, press the power button, and hold down the "D" key, the system boots up as normal and does not enter the AHT.

The File/Folder Finder sticking to the mouse pointer issue is very annoying. Does anyone have a solution to resolve this issue?

- Cheers