On the new MacBook Pro, try this: - Open an app where pressing up/down changes something (maybe a text document with multiple lines) - Rest your finger on the arrow up or down key - Start increasing the force you're applying to the key until it "goes in" and basically gives you feedback - Did the onscreen cursor move? Meaning, did it register as a press? It seems that you need to apply a greater force on the key than what's required for the feedback to make it count as a press. Once you notice it, it's really easy to replicate. Note that this does not happen on the arrow left/right keys, only up/down. Are other people having the same issue?