I have Vista and i have teathering and bluetooth teathering set up just fine. Just reload the DM software and go the the normal steps to teather just like XP and your good to go. Also when using the bluetooth I have speeds of 925K
pretty fast!! with a little MOD of the modem settings! its the same steps as XP just make sure you click all the prompts and change propertys box in the modem settings or it wont let you do anything.. Also you have to reinstall the DM to install the driver properly!
EDIT: I have found that everything works perfect on Vista so don't let this hold you back from upgrading its a great OS!