I think mine "creaked" too but I remember some of the buttons started to like loose contact, in that you had to press them harder before they'd work and then eventually I lost them entirely. I believe it's because the forward half is so thin that the "moment arm" stress of pressing the buttons nearer the front while holding it with a normal grip at the thicker part, causes it to repeatedly bend and eventually the circuit board develops a hairline fracture. I never took mine apart to see because I took it back for a refund.Ive noticed a lot of creaking, and the volume and channel buttons suck on this one (been using my denon remote for volume). Now that I like Harmony, looks like an 880 is in my future (same price as a 670 right now on Amazon $120). I do like the Harmony control otherwise, great setup.
I also like the Harmony concept and have been happy with the 670, which is built much better. Just need to get an IR adapter so it can also run our PS3. I had thought the USB module that Logitech includes with their game controller would work for their Harmony remotes but mine didn't.