6265i and Bluetooth Internet Access

I've a 770 Tablet, and it uses the 6265i for Internet access - working
wonderfully!

However, attempting to use the Macintosh MacMini with the same phone
(6265i) it connects, sets up PPP, and is immediately hung up on by the
remote side after establishing IP address and other details.

I've tried changing PPP settings on the Mac with no success. I copied
the data from the Nokia 770 (number #777, user, password) and had no
better success.

I tried examining the details on both systems for PPP configuration
and logs (since I am a UNIX administrator after all) but found nothing
in the Nokia 770 (Linux) settings or in the Macintosh (BSD) settings
that I could identify; both are different enough from the standard set
up in order to be confusing.

What am I missing? In short, the Nokia 770 + Nokia 6265i team works
well, but the MacMini + Nokia 6265i does not work.

The MacMini is a Macintosh MacMini with 1G memory and Apple MacOS X
Tiger 10.4.8; the bluetooth connection is provided by a ioGear USB
bluetooth adapter. File transfers work just fine to and from (both
with the 6265i and the 770).

Can someone help?