I have the same issue. Even restore did not help. Right now my brand new IPod touch is just a very expensive MP3 Player with the capability to bug me to death.
That was really an eye opener for me, since I always thought

products would be stable and user friendly. But what apple demonstrated here is a total lack of support since this bug seems to be very common for a looong time already and no bugfix or any statement from apple is to be found.
Luckily I bought the pod before I decide what new phone i want. Till now i wanted the 3GS but after this expereince i think i give an Android Phone a shot......
Good luck to you all.