Unwanted keyboard bahaviour: <ALT GR> rotates screen !!?

[FanOfThinkPad]

Hello,

I own a T410.
If I'm logged on (Win 7) , pressing <ALT GR> rotates the screen.
Pressing the <ALT> key will run various programs.

With an external keyboard the mentioned bahaviour does not occur!

Is there a (Lenovo) tool where I can setup the keyboard behavior?
(Until yesterday, everything works perfectly. I only installed a new printer driver.)

Many thanks for any hint!

Regards
FanOfThinkPad