I want to calibrate my display using the built-in calibrator (Preferences > Displays > Colors > Calibrate). This worked great in the past, but since last week it behaves strangely. When I start a calibration and move the value-sliders (like in the "can you see the apple" step) the display automatically re-calibrates after I release the slider. That means: I set the slider to make the apple vanish, but when I release it the display flickers and is recalibrated, so that I can see the apple again.
The same happens when I switch the color profile. The profile is applied for about 1 sec but then the display "calibrates" and changes its colors, while the profile stays selected in the Preferences.
I have checked my display's hardware settings (on-screen display) for some kind of auto-calibrate setting but there is nothing as such.
I have also tried to reset the Parameter-Ram of my Mac, but this had no effect.
What could be causing this odd behavior?
I'm on Mountain Lion.
Update: This occurs for my admin user only. When I switch to another user everything works fine. So this must be a Mac OS issue, no hardware problem.