I found exactly this issue with all the Nokia 3G's they use the newer symbian OS which is not totally compatible - allows you to receive / make calls but no phone book transfer. I now have a Sony Ericsson K608 which is 3G and is perfect with phone book transfer and receives SMS's.
Your reconnect / disconnect could be down to the number of SMS messages you have...try removing them all (inbox / sent etc) and see if that helps

Steve