Just want to point out that this is not a solution, this is a TEMPORARY fix. My phone is having the same freezing problems (along with 3 other major issues) and Verizon's answer was to send me a new phone with a new set of problems. Yes, you can reset your phone by pressing the power and the volume-down buttons for ~10 seconds, but this doesn't fix the problem. Rather, it just resets the countdown until it happens again.

Verizon (and believe me I have posted this on the Windows forums as well) - I challenge you to fix the multitude of issues with the Nokia Lumia 928. It is a great phone with what seems like very fixable problems.