I'm lost! I'm trying to pair my Palm Tungsten with my 6310 and discovered there's something called a "passkey". So I dig into manuals and read in one I must create the passkey, and in other ones that there's a fixed passkey!
There is no fixed PASS KEY on the 6310. When prompted for a Pass Key, enter any number. Once you have entered this, the device that is trying to access your 6310 will ask for the Pass Key as well. Enter the Same Pass Key number in the accessing device and you will get a successful pairing. Once Paired if you trust the Accessing device change the settings for the device so that you do not have to enter a Pass Key every time.
EDIT: For further clarification please see: http://nkn.forum.nokia.com/devrel/threadshow.cfm?mb=4232714880360102&msg=3000905574820212&page=1