This problem is a real annoyance. I'm a digital artist and use a tablet quite often. Lately I've been trying windows 7 out and I really like it. Only my tablet doesn't work quite right. I have the drivers installed and all that, and the tablet pen works fine inside photoshop. But when I minimize photoshop to say, look at reference photos, I can't use the pen anymore. I have to use my usb mouse. Back in photoshop, pen works again. I don't get it. I did uninstall the windows tablet pc features, and I thought that may have been it, so I reinstalled them, but it still doesn't work. I can actually go into the settings of the tablet, change the pen to work as a mouse and it works no problem, but that's horrible to draw with. In windows xp I could easily go from program to program, using my pen to click on icons, task bar, etc, while still in pen mode, but not in Windows 7 it seems.
Any ideas would be helpful.