After some painful attempts to tether my BB 8120 (T-Mobile) to my MacBook Pro (OS X 10.5), I did the unthinkable and… called support! I thought I’d share my find, just in case anyone else out there is struggling.

1. Make certain that you’ve deleted any previous Blackberry modem scripts that you may have installed.
2. Delete you existing pairings from both your phone and laptop.
3. Download the latest modem script from this site. Yes, believe it or not, T-Mobile’s tech support sent me to this script.
4. Unzip the file and drop the entire folder Blackberry.ccl into the following folder: Macintosh HD > Library > Modem Scripts.
5. Open System Preferences and go to Bluetooth. Click the little + icon to run the Bluetooth Setup Assistant. Run through the setup. Pretty straight forward, although you should be searching for “RIM” or “Research in Motion” in the Vendor field. You may be asked to complete some settings now (if not this will happen in the next step). Here are the settings:
   • Telephone number – wap.voicestream.com
   • Account name – gprs
   • Password – gprs
6. Next, open the System Preferences and select Network. Select the Bluetooth icon on the left. You should see all the settings from the previous step. Click Advanced. On this screen, check that the “Enable error correction…” box is unchecked. Also, dial mode should be set to “Ignore dial tone…”. Select Ok.
7. Now, give it a try. Select the modem icon from the top right bar on your Mac and select “Connect Bluetooth”. It should work!

One thing to note is that the first timeI tried this with support, it did not work! I had to delete the Bluetooth connection and the Network connection and (after a reboot of the phone and laptop) start over.

Hope this helps