After about a year the first activity button on my 550 started needing several presses to work. Does this sound like a pending hardware failure? Is it common? My remote is used daily and my solution is to swap the activities assigned to buttons 1 and 3.

If buttons 2,3 and 4 each last a year I'd be more than happy.

I had a 550, but never opened the case. But, if it's like a lot of electronic devices with buttons, you may be able to open it up and clean up the contacts on the circuit board, and the underside of the keypad that makes contact with it. You'd be surprised how dirty and oily these things can get inside (and maybe someone spilled something on it and never told you). Just be very careful in case there are any loose parts inside.