Its quite apparant that Nokia refuses to ansver this kind of questions, simply because that they have reveal that this is one of the ways of making yet more money.
To do Synch through Bluetooth, you HAVE To buy Nokia Bluetooth adapter for your PC. This is because you need the little piece of software called something like the "OBEX profile handler".
OBEX is just one profile for bluetooth devices. Other profiles are DUN, SPP and WAN etc. Nokia could have included the OBEX module with the phone, just as they did DUN and SPP. But then - who would buy their precious Bluetooth adapter, with a nice Nokia logo printed on it.
The PC Synch software, that is working fine with IR, which also has a OBEX profile for IR, can not be used, because the PC Synch has a hardcoded restriction that makes the PC Synch refuse to see bluetooth devices, that do not come from Nokia.
They wont tell ansver mails of this kind, for obvious reasons. :-)
RE: 6310 and syncronisation via Bluetooth
You can synchronize contacts and calendar if you have installed the Nokia PC Suite and the Nokia Connectivity Card DTL-4. Alternatively, you can use some other manufacturer's Bluetooth solution that is compliant with Digianswer's Bluetooth PC software.
Further information on Bluetooth in 6310 (including technical specifications, accessories and FAQ):