Hi Buckie, I was also tearing my hear out after installing Vista and the Wacom drivers. Apparently Vista has pen functionality built into all versions (much like the Tablet PC editions of XP). This however conflicts with the wacom drivers resulting in a sort of double driver issue. After browsing the Wacom forums I found a solution that works for me (Vista Ultimate 64 bit)
Go to the windows Control Panel (not the wacom)
Select System and Maintenance.
Select Device Manager.
Under Human Interface Devices disable the Wacom Virtual Hid Driver.
This will disable the windows part of the tablet driver and allow the Wacom driver to work as it should. The tablet will work like in XP except that Vista PenEnabled programs lose their tablet functionality.
Edit: If you reinstall Vista at some time try turning off Tablet PC Optional Components before installing the Wacom driver. That should give you a pure XP experience. Look under Control Panel > Programs > Turn Windows Features On/Off.