Great... once I had posted the question, I found the answer:

from: http://www.excelforum.com/showthread...hreadid=382012

According to VBA, the choices for ActiveSheet.PROTECT a

expression.Protect(Password, DrawingObjects, Contents, Scenarios,
UserInterfaceOnly, AllowFormattingCells, AllowFormattingColumns,
AllowFormattingRows, AllowInsertingColumns, AllowInsertingRows,
AllowInsertingHyperlinks, AllowDeletingColumns, AllowDeletingRows,
AllowSorting, AllowFiltering, AllowUsingPivotTables)

To prevent users from selecting protected cells,
"ActiveSheet.EnableSelection = xlUnlockedCells" has to be set additionally...
(however, some more problems occur here as this function is - unlike the
manual setting - not persistent when performed via code.

So, sorry for bothering the community ;-).
Cheers,
Philipp