thanks for your answer!
I'm cleaning up in my MBP and discovered 2 maps called "iBook". They both contains the contents of my old iBook even though they are not absolutely indentical....3 years ago I copied the contents of the iBook to the MBP when I started using that and later on I've made a copy from one MBP-partition to another. Terrible mess, I know:-).
However, there are (at least) 2 maps that I can't get access to, there is a "red traffic stop sign" attached to the map in the lower right corner. BUT it is just in one of the "iBook"-maps there a stop-signs, in the other they have the same name + "2" (version 2).
I have looked at the info for the map but the "unlock" checkbox is not awailable, it is "greyish" (and it is not checked).
I did take a screenshot of the map but it was not allowed as an attachtment eventhough it is only 20 kb. It is a tiff-file.
Hope this long explanation helps:-)