Does someone knows what it means when this message is shown, when you start itunes: "an unknown mistake has occured (-42032)"

Have you looked at the previous discussions listed on the right side of this page under the heading "More Like This"?

Also:

"Error 42023" through "Error 42408"

These alerts might occur when trying to authorize iTunes or during launch when iTunes checks for authorization information.

1. Install the latest iTunes from apple.com/itunes/download/
2. Remove the SC Info folder.
3. If that does not resolve the issue, see iTunes: "Error 42408" or "Error 42404" after upgrading to iTunes 9.0.3.