Have seen numerous postings with people saying they get multiple key presses like "uuu" when pressing "u".
This also can happen with the menu key.

I believe this is a keyboard membrane issue. I had a bad "u" key where the action (like piano key) or click had gone but the key still worked. When I looked at the membrane under the keyboard the membrane dome had collapsed, so I ordered a bunch of cheap membranes from Ebay in China, but now after a short time installed I am getting multiple keys giving me 'double presses'. I believe this to be the cheap quality membranes not giving enough upward force to counter the key press.

Ordering OEM membranes this time, lesson learned, cheap isnt always best.