Help! My command key "sticks" on ML GM!

[blueandwhiteg3]

I recently installed the 10.8 Golden Master - 12A269 - on an early 2011 quad core MacBook Pro 15" machine.

The moment I rebooted from Lion into Mountain Lion, I found a new and most troubling behavior - my command key is "sticky" now. If I press and hold it for 1 second, the system will act like I held it down for 2 seconds.

Essentially, any time I press command, it is triggered for twice as long as I had intended. This is incredibly irritating when I am moving fast on the keyboard. For example, I open a new browser window using command-N and then start typing macrumors.com, the M causes a command-M to be triggered and minimize the window. It leaves me wanting to punch the screen.

I have reset the SMC. I have reset the PRAM. I have verified the dmg. I have even setup a new partition and done a 100% clean install of mountain lion. The behavior remains the same. Always.

I checked accessibility. None of the features like "sticky keys" are on. I even tried turning it on and off. I fiddled with keyboard settings.

No other keys are affected, not even the option key. Both command keys (right and left of space bar) behave identically. The 2x interval is exact, so it seems likely software-related.

Does anybody have any ideas before I rip my hair out? I am constantly doing unintended things with this behavior.

 

[RKO]

I doubt it will be the Mountain Lion install. See following thread. Maybe a hardware fault in the keyboard.
https://forums.macrumors.com/threads/1160670/

 

[David085]

sounds like a troll.
sticky keys option in Apple OS I doubt that.

 

[blueandwhiteg3]

I am not trolling here. I have a legitimate problem that is baffling me.

Regarding the stuck key post, I have read threads like that. Please read my post carefully. The key is not permanently stuck, instead, the problem is that the key is active for twice as long as I pressed it, every single time. (I have an app that shows me key press events and their timing.)

I do not believe it is a hardware keyboard issue. How would a hardware keyboard failure cause the duration of the key press to be precisely doubled, every time, from either command key?

Moreover, even if it is a hardware issue, how likely is it the hardware problem occurred in the relatively short period of time while Mountain Lion was installing? The computer was just sitting unattended.

I will install Lion on a second partition soon to test further. I can also move my SSD into another MBP to test some more. It just takes time and I've already been through an awful lot of tests for tonight. Let's hope there's some useful posts in the morning.

 

[RKO]

I did read your post carefully and did offer some useful information to help with your issue. Good luck and hope you have it sorted by the morning.