This is more of a "what not to do" -- I just thought it might be useful to someone else out there who might be as dumb as I was today. I'd imagine it is a pretty uncommon situation.
My front silver buttons started freezing today. I thought it was app-related and I even did a factory reset to no avail. What I didn't realize is what ELSE I changed about the phone at the same time I installed several apps...
I had added a bumper-case to the unit, one of those rubber silicone ones.
This case is great except for some reason instead of leaving HOLES for the power / volume / camera buttons? They just made indentations out in the rubber and kept them covered. To keep dust out I guess? This is nice in theory, but trust me, it is a poor design because rubber obviously stretches and moves. That's kinda the idea. But the rubber indentations are precise, and if the rubber moves even SLIGHTLY one way or another, your buttons are going to get pressed.
So what was happening is that the rubber of the case was contacting the volume keys and holding them down. This apparently caused the phone to lock out all the other keys, except the power button thank goodness. The screen was also fully functional.
I was frustrated and I held it up to my husband and said "Look, I can't even turn up the volume" (*demonstrate*), it's almost like... (*pulls the rubber away from the volume key*) ... (*press volume up and volume goes up*) ... Oh... crap."
Ironically I had did a search on the 'net for "frozen keys" for the X10 and found several people out there reporting such a problem. Now maybe their problem was legit hardware failure, but maybe.. just maybe.. one of those people might have experienced something like this and would get use out of this info.
Anyway, just wanted to put it somewhere.