The path to the lens profiles under Win7 is wrong. On my PC it is C:\Program Files\Adobe\Adobe Photoshop Lightroom 4\Resources\Lens Profiles\1.0. This should also be mentioned in the Readme file, because it differs from LR3. I had used home made profiles (created with ALPC) in LR3 and was astonished that they were not being used by LR4 before I copied them to the new location.
"Rand entfernen" shown at the bottom of "Objektivkorrekturen" is not explained. The term is not self explaining. Does it mean "Farbsäume entfernen"?