I have a nokia 6500

i have a nokia 6500 slide on a contract from 3. Up until recently the phone has been fine. It would connect and sync to my pc without any problems, and accessing the internet through the phone, to my pc was fine. Recently however, the phone seems to have become very unstable. My pc always recognises it when it's plugged in, but internet diwnload times have got slower. Half of my contacts have dissappeared, and now i cant copy things from the memory card either. When i try this i get a message saying that the device is either not present or in use. Also, i can no longer sync it with outlook, the message tells me that it has to be in an idle state before sync can take place.HELP!!! I am a bus driver and so work very unsocial hours and have a feeling that if i contact 3 about this they will just tell me to take it into a 3 store, which i am unable to do. Any ideas?