I'm quite sure no one wants to part with their handphone at the Nokia Service Centre unless warranted as it will take some time to repair. I still remember when I sent my Nokia 3310 for service, Nokia Service Centre, Malaysia requires a time frame of least 2 weeks although they may complete the job earlier. Thus, if my handphone seriously hangs, I will always do a factory reset followed immediately by a software update. Even Nokia Service Centre advised me to do a factory reset first and if that fails, they told me if could be one of 2 possibilities: firstly, a hardware issue where the faulty part has to be replaced to put it back in good working condition. They said if it is under warranty, they will even go to the extent of replacing whatever needs to be replace although it may be more expensive than giving the owner a new replacement handphone because for auditing purposes it does not make a good clean history of servicing record. Secondly, if it is a software issue beyond their control, they will simply say you have to wait for the next update and hopefully it will remove the bug. (Hopefully) So bringing it to the service centre is not full proof that your problem can be solved there.