[teemuv]

I use alarms and snooze regulary. Display gets somehow stucked on that position where snooze buttons was. Later same day active phone call gets hanged (or some apps get started by itself) because the hang button (or apps) is same place as snooze button was.

Could it be caused by screen protection film or what is this?

[tiny_chef]

The phone is equipped with proximity sensor which disables the screen during call. This is to prevent ending a call by accident. Since you are dealing with multiple issues with the device like freezing and sudden opening of applications, you can try these troubleshooting steps to isolate the issue: http://support.microsoft.com/kb/2606900

[teemuv]

I forgot to mention that i use bluetooth headset during phone calls and phone is on table.