It's an odd that we can't use Tablet features in Photoshop if you are using Tablet PC with Multi-Touch screen (Both active and passive digitizer) Although a pen sensitivity works flawlessly with every other programs such as OneNote, Alias SketchBook, InkSeine, or even Paint.NET, it just doesn't work with Photoshop. Yes, you could draw on it, but without sensitivity? why do we have to use an active digitizer? passive one should be enough.. Okay every problems have a solution. This still applied. Just for a reference, I am testing on Thinkpad X61 Tablet Multitouch, but this is a problem of all Multitouch tablet.
The problem is Photoshop can't recognize the Wacom pen on Multitouch screen. In other words, an active digitizer on Multitouch Tablet PC will not work in Photoshop. I don't know if this should be a Adobe or Wacom issue though. But if I have to answer, it should be Adobe that needs to work with Wacom about this since other programs work just fine. From this problem, when you draw, you will get something like this.
You can tell that I'm not an artist or any kind close to that. So don't laugh at me :-/ As you see, what you got from original driver of you tablet. Isn't worth using tablet at all....
Here is what you have to do, you have to go to Wacom website and get a bamboo driver. Then installed it. Easy, right? You will get something like this instead:-
I'm not quite sure which one is better--still kid drawing :-/ but you can see a difference, big difference since an active pen is working properly now. Nonetheless, this is not a permanent solution at all because touch--or passive digitizer--will not work under a bamboo driver. It means that you will be able to use only Wacom pen, mouse and keyboard--not your finger. If you want to touch again, you just have to install multitouch driver. Then everything will be normal again--Photoshop will not recognize active pen again. In case you want to use Photoshop w/ active pen in the future, all you have to do is reinstalling a bamboo drive back and forth again and again :-D
I don't know when this problem will be solved permanently but now, at least, you will be able to get an advantage of your machine. "May the active pen be with you"
updated--same day--12:44pm: After I messed with all this, I might get Multitouch work. I just need to check about it to see whether it's going to last. Up to now, they are still working after several restarts w/o tweaking a bit. Stay tuned!