Wow that's pretty unfortunate
Just to clear anything up (being the first person in the tour and all), I'll say again that I experienced the unresponsive/key repeating issue on the first time I plugged it in an tried it out, then after reconnecting the USB cable, it worked perfectly fine for the rest of the week, except one morning throughout the week, where I experienced the same issue again.
I most definitely didn't take it apart; the extent of my fiddling was changing the DIP switches while the kb wasn't disconnected, and popping off one cap. I kept it at work the entire week, locking it away in my desk after each day.
I didn't try another USB cable, but it seems unlikely that a bad cable could be responsible for this type of behaviour. I hope it really isn't anything too serious though...