bluetooth from iPhone 3GS to MacBook Pro not working?

thanks - I think I've covered this but I'll go through it all again tonight...

Question - Is it necessary to have the hot spot running on the iPhone prior to trying to establishing the bluetooth connection from the MacBook to the iPhone?

thanks - will check again at home - I didn't want to confuse this post question however I also can't seem to teether from iPhone 3GS to MacBook Pro via USB either...so kind of feels like something more sinister...

Additional note - Should have mentioned I can teether successfully from my iPhone 3GS to our iPad 2 (so it's just when trying to teether to my MacBook Pro I'm having the issue)....

nothing in these articles helped unfortunately - some more clarification:

• tethering via USB from iPhone 3G to MacBook Pro => WORKS
• tethering via Bluetooth => does NOT work, with bluetooth connectioning not staying up

During pairing process:

• devices "see each other"
• pairing appears to work, then you see that the connection drops out directly afterwards (almost immediately)
• on iPhone message = "Connection Unsuccessful - XXX's MacBook Pro is not supported"
• on MacBook - it's just the connection in Bluetooth options shows up as not connected
• in /var/log/system I see some bluetooth related lines:

Apr 18 19:33:14 Gregs-MacBook-Pro bnepd[18950]: [IOBluetoothDevice instantiateChannel] BluetoothHCIAuthenticationRequested failed (0x0006), so retry

Apr 18 19:33:14 Gregs-MacBook-Pro sandboxd[18966] ([18950]): bnepd(18950) deny mach-lookup com.apple.blued

Apr 18 19:33:14 Gregs-MacBook-Pro bnepd[18950]: [IOBluetoothDevice instantiateChannel] BluetoothHCIAuthenticationRequested failed (0x0006), so disconnect device

Apr 18 19:33:53 Gregs-MacBook-Pro blued[22]: Removing Bluetooth configured device: 00-26-08-23-23-9d

Any other ideas? Is it a physical problem with my MBP? but then again my bluetooth mouse stays connected ok. And in terms of the iPhone well it tethers fine to the iPad via bluetooth....