I have the same problem with unresponsive keys as well. But I want to clarify. The keys are only unresponsive when the device goes to sleep. So when you set it down, and leave it for a while, the screen goes blank (not in standby). You normally can press any key to get it to respond "wake up".
But with the Otterbox case on, when you press any key it does nothing. You have to press and hold the key (any key) for a couple of seconds. Once it's awake everything seems to work great though.
The big annoyance is that without the otterbox case, when you press a key it does not perform the function of that key, just wakes the device.
But with the otterbox when you have to press and hold the key, it performs the function of the key. So in my scenerio I had gotten accustomed to just pressing the right-convenience key to wake up the system without launching the camera (which is what my Tour is set to do with the right convenience key). But when I do that with the Otterbox, I have to hold down the key and so it launches into the camera even though I just wanted to "wake" the device.
I've tested it with and without the entire case and had the problem.
I've tested it with the full case but without the keypad protector and still have the problem, even when pressing the unprotected keys or the trackball or convenience keys. You still have to hold the key down for a few seconds. (I thought for sure it was a problem with the keypad cover, but this proves it's not).
I then take the rubber casing off and the problem goes away when all there is is the hard plastic shell.
I then placed the device on a shipping envelope lined with bubblewrap (thinking the problem was with the resistance on the device). I still did not have the problem.
I then went a step further and placed it on a bag of shredded paper (which would have almost no resistance). But it still worked.
I then put the silicon seal on, only securing the top half though, leaving the bottem half hang loose. No problem. Keys work as expected.
I put the bottem half on and the problem returns.
I then loosened the charing port cover like you would if you were going to connect the charger. No problem. Keys worked as expected.
I replaced the charging port cover, and the problem returns (my cover has the problem too where the charger doesn't fit in the port without modificaition. NOt sure if that's related).
So the conclusion is:
charging port tab in - keys stick
charing port tab out - keys don't sick
My theory is that when you pull the tab for the charging port to get it in place, it puts more pressure on one of the keys (most likely the right convenience key) and may actually be pressing it in a little, making the other keys unresponsive at first. With the tab out, the pressure is relieved and it works as normal.
The scientest in me wants to totally figure this one out. The employee in me wants to get back to work on things that really matter

.
Can anybody else confirm these results?
Hopefully this helps the Otterbox folks figure this out.