wannawatch, I've gone through a few Harmony/Logitech remotes, and the buttons have always worn out quickly. If pushing down the metal "bubble" directly doesn't work, then your problem is likely not fixable without some soldering at the very least.

The reason I keep going back to them is the ease and flexibility. I suggest simply remapping the broken button's function somewhere else; you'll probably get used to the change quicker than you think.

Now if I only had the skills to solder back the mini-USB jack to my H880 board I'd be set for another year or two, but there are multiple pins, and I've never soldered before. :| Oh well, it's lasted me as long as any other H/L remote I've had.