On a Gateway M-275 convertible notebook, after installing RC1 build 5728 the
TabletPC buttons showed up as an unknown device. When I tried to update the
driver and allowed Vista to search on the Internet the unknown device was
installed as TabletPC Buttons.

When I pressed the Screen Orientation button on the notebook I got a screen
that listed various functions such as Log Off, Switch User, Task Manager and
more on the same background as the normal login screen. The only way to get
out of this screen was to log off and then log back in. After this the
button did not have any effect when pressed until I restarted, when the same
thing happened.

I ended up uninstalling the TabletPC Buttons device and then I installed the
driver for Windows XP downloaded from Gateway.

So obviously something is wrong with this driver that Vista found.
Incidentally, Windows Update wants to update to this driver so I hid it
there.