P8000 Turns itself off when in lockmode.

Got my new elephone yesterday, and it started to giving me problems right away.

When i lock the phone, it turns off. It works fine aslong i use the phone.

I have tried Roms:
Eragon 2.5.0 - turns off when locked
Stock 15 07 25 - turns off when locked
Stock 15 09 07 - turns off when locked
Stock 15 09 09 - doesnt turn off when locked, but no simcard detected, not invalid IMEI.
Flyme 4.5.2 - turns off when locked

What is wrong with my phone, can someone give me a solution on this? or do i have to wait for a stable ROM?

WTF!!!!

Im thankful for all the help i can get.