MacBook Pro keyboard problem!

oreius, if it’s any consolation, my MacBook Pro behaves in the same way. (I haven’t tried running Garage Band yet, so I hadn’t had a reason before to try to press three keys simultaneously.) My keyboard layout is Japanese, so the right-hand keys in the middle row are J K L ; : ] (there’s one extra key before reaching the Return key).

Here are the three-key combinations in the right-hand section of that row that work as expected (in a Terminal window):

JKL JK] J;: J:] KL; KL: K;: K;] K:] L;: L:]

All of the other combinations only produce one or two characters.

My first guess is that it’s a software issue, since I sometimes see a slight delay between the keys being pressed and the characters appearing. I do have [KeyRemap4MacBook|http://pqrs.org/macosx/keyremap4macbook> installed, so theoretically that could have affected my results; but since I haven’t used it to alter the behavior of any of those keys, I don’t think that it’s playing a part in what I’ve seen on mine.

If you have an external keyboard (I don’t), it would be interesting to know if you see the same results while using it as you see with using your built-in keyboard.

oreius, if your local Mac retailer is nearby, perhaps you could try some three-finger tests on some display models, to see if they act the same way also?

That your external keyboard works well could suggest that the behavior is hardware-based rather than software-based. Have you tried using your preferred search engine to look for “N-key rollover” or “NKRO” regarding your MBP, which apparently is the technical term that describes the ability to correctly handle multiple keys simultaneously?

My 2010 MBP does this as well, and so has just about any other computer (Mac or Windows) I've ever had. It's a hardware problem with the keyboard, and the combinations that don't work can vary between different keyboards. No software fix for this unfortunately.

Some keyboards are specifically made to register a much greater number of keypresses than regular keyboards, but they're generally more expensive (example: http://www.steelseries.com/us/products/keyboards/6gv2/information )