I agree, update the OS on the Bold. I had the same issue with mine running an old OS.
As for the BlueTooth modem on the Mac, here is a link to the scripts if you are running 10.5. Updated Modem Scripts for OS X 10.5 (Leopard) - Fibble.org
It works nicely. I use the script for the 8800. When I was actually using an 8800 I would only get one session before a hard reboot of the BB was needed. With the 9000 there doesn't seem to be the same problem.