OK... This still doesn't make sense. I can sometimes get the BlueTooth DUN to work, but I am now not sure if I can detect ANY pattern at all in when it works and when it doesn't. My previous posts indicate that I got it working by creating a new Bluetooth DUN network interface in Network Prefs, with a new name. I now think that may have been a false clue. It seemed like it worked a few times, but then it didn't.
I have another possible clue, in that I can sometimes get it going using the original Bluetooth DUN interface (deleted all the rest), if I turned on PdaNet as the FIRST app after shutting the phone off an turning it back on... Again, not 100% of the time, but it's something to try.
Eventually, I hope PdaNet gets updated to work right with Android 2.01, but for now, I'm just trying to find a work-around... especially since my cable-modem is on the fritz and won't get fixed for a few days. I am posting this via the Azlink solution mentioned here.
In the mean time, I've gotten "AZLINK" to work. It's another USB tethering solution, but it's not in the Android Market. It's at:
azilink - Project Hosting on Google Code
The developer is not especially detailed in his instructions, but it can be made to work.
The first hurdle is downloading and installing the Android developers SDK... I happened to have downloaded it the other day, because I'm interested in programming Android apps, but all you really need out of it is the one utility program "adb".
The next hurdle is that the OpenVPN site he mentions doesn't have a Mac version... luckily, there are several OpenVPN programs out there for Mac, the one I chose was TunnelBlick
tunnelblick - Project Hosting on Google Code
Next, the AZLINK OpenVPN configuration file is named aziLink.ovpn, but TunnelBlick doesn't want that file name. You have to re-name it "azlink.conf" and copy it into the Configurations folder for TunnelBlick, located at ~/Library/Application Support/Tunnelblick/Configurations
Once you have the pieces in place, you:
1) start Azlink on the phone and check Service Active
2) run the adb command in the mac Terminal (outlined in the instructions and repeated in the About area of the Droid app itself in case you forget what it is)
3) start TunnelBlick and connect to the VPN defined by the azlink.conf file.