It seams that PC Suite 4.81 for 6310i is NOT compatible with USB accessories.
I have worked fine 14 month with my "old 6210" and my Sony PCG-R600 notebook unsing an external USB IrDa adapter Bafo BF-120.
My 6210 died. I selected the professional choice compatible with my 6210: a 6310i.
But the 6310i and the PC Suite 4.81 don't work any more (with my IrDa adapter).
I buyed an USB MSI Bluetooth adapter.
I can communicate with the phone, but NOT with PC Suite.
After a long call to the support service, it is "officialy clear" (where ? only when you haye the problem, it's become official) that Nokia DO NOT SUPPORT USB adapters.
Nokia mobile ??????
Yes, but only with Nokia accessories !!!!
And only with PCMCIA card provided by Nokia of course.
So if you buy the DTL-4 connectivity pack, you will have a chance to be mobile !!!
If anyone found a solution to communicate with an USB adapter (IR or BT) and PC Suite, I will appreciate.