Nokia Nseries :: N8 Contact List Freeze?

Every now and then my Nokia N8 contact list freezes when I try to select a contact fom the list, when starting a call or by accessing the contact list directly. A reboot, factory reset nor firmware reinstalling doesn't solve the problem, it only works temporarily. When the list freezes I am able to swipe through it up and down, though selecting contacts is not possible. I do see a cursor blinking in the lower half of the screen, at the position where the search window normally is. The search window itself is vanished.