This is the problem: Suddenly, you double click on desktop Wacom tablet settings icon, and it won't show the dialog. It appears to be loaded as it's shown down in the Windows taskbar. I suspect it is caused by change of resolution or some setting, maybe suddenly it sets the origin of the panel dialog at some 3000 pixels to the right or something. I have dug in the wacom_tablet.dat file to see if I can fix it changing some value there, but it looks like a log, a history, more than a ini for settings. And anyway does not solve it.
My solution is having always a very complete settings file done and backed up to restore (with Wacom utility for this, which in previous driver versions did not exist) when this happens, but it is counter-productive: You change the settings even per each project (and software) needs. I have seen it happenning with Cintiq 12", intuos4 A6, Graphires, Intuos 1.
Is it just me, doing something weird every time? I doubt it, it's normal use, I am amazed that it seems no one else has had this problem (or nobody asked). It happens often with typical use. Maybe it's because I'm setting a shortcut in the desktop? Weird as it works perfect until some random moment.
(I have dug in Wacom's forums and FAQs, then here, but nothing related to it. Neither in "related questions".)
The thing happens in Win XP, 7, etc. It's done so for years in my experience, and several times at work, which is worse.