Hi guys and girls!

Unlocked my iphyone 1.1.2 otb with turbosim (Movistar spain),...and it works fine....BUT when the autolock goes on and the phone goes to sleep...anyone that calls me gets my voice mail and when i unlock the keypag...it unlocks the sim again and i get the service back...

Can anyone tell me why....and how i can fix this=?

Cheers!