I'm having the same problem with my Cintiq 21UX even running the latest 614.3 driver
. Sometimes I restart and the driver will be operating, sometimes it isn't. I can't figure out the specific "what is it" that is causing the issue.
Also, I don't have a PTZ icon nore a Tablet Preference File Utility in my "Devices and Printers"
A Wacom Tablet Properties icon shows up in my control panel, but when I click on it when the Wacom isn't working I just get a "THE TABLET DRIVER WAS NOT FOUND" dialog box. This of course works fine when the tablet is magically found.
It pains me to say that I never had this issue on Vista. This issue is beating me up pretty bad with the project I'm working on. Any feedback/ideas would be greatly apreciated!