Had exactly same issue here. After accidently destroying my Lumia 925's screen allready for the third time (Allthough phone still works after a swim in lake in my pocket, drop on concrete and beeing forgotten on bonnet with all the consequences. I would suggest it is in quite perfect condition - only the screen should be replaced and blown vibra and button's backlight fuses changed) I went for a new Lumia 830. The first glitch I noticed was an oversensitive search button. If screen was set to very-sensitive mode (in order to use it with gloves) the search button would hit by itself. It's kind of disturbing when you read some news, write an e-mail or just play some game. So I switched back to normal sensitivity and the bug was gone. By then I was planning to return the phone to my carrier after six months mandatory period and repair my Lumia 925 once again. After a month or so I was wiping the screen and noticed that funny glue-sticking-noise. Looked carefully and found out that I was able to stick my VISA easily under it. So the next morning I took my 830 to my carrier's office and they accepted it on behalf EU warranty regulations or whatsoever. The guy in shop said it's not the first time him seeing a loose screen on 830. So after 6 days my phone is back - the screen has been replaced, everything looks firm now and I didn't have to pay a single Eurocent for that. Let's see if that fix holds and I am thinking about rather keeping my 830 than reanimating the 925 for now.