i encountered the locking issue last week for a couple of days, mainly through the pocket express app. it would freeze the phone whenever i tried to view or update the news or weather. it finally cleared itself out and is now humming just fine.
for anyone having this issue, if you bring it to a store which has a cellebrite machine for transferring contacts.. if they innitiate a contact transfer it will unlock the phone automatically and you can then go into the settings menu and reset the factory settings. You must unplug the instinct from the cellebrite before it finishes the phonebook transfer because that will cause the phone to powercycle and the password will come back up.
That happens to me all the time, and it's usually when someone is leaving me a voicemail. Of course I usually don't know I'm about to get a voicemail until after my patience is gone, but I've opted to take the battery out and put it back in a wait even longer for it to reboot, instead of smashing the phone all together. Sometimes I do have the patience to just wait and see if it unlocks, but that normally only happens if I didn't answer a phone call beforehand, and assume that maybe I'm going to receive a voicemail, so I might as well just wait.
Just in case you're talking about something completely different, once my phone would go to something way different than what I wanted it to go to, and I finally figured out that there was a teeny tiny bit of condensation just under the touch screen. I was able to sort of peel it back a little bit and carefully get a piece of tissue under there enough to temporarily fix the problem, but then I took it in to a store and they did something to it, but told me that I needed a new touch screen, and that they ordered it, and I would have 14 days to pick it up from that store. I wasn't able to get back there to pick it up, but I didn't need to. Whatever they did at the store solved the problem and it was just like new. By the way, I would not recommend peeling back the screen based on my comments. It could void warranties, etc...I was just lucky that I didn't mess mine up.
Maybe that's the problem, maybe not, but hopefully neither one of us find ourselves in a position where we need to call 911 or something when that's happening!!!