[TYPO3-dam] Indexing after upload in DAM Element Browser does not work

[Peter Kraume]

TYPO3 4.4.6
DAM 1.1.8

After uploading a file in the DAM element browser the file is not 
indexed. Upon trying to edit it, I end up with the error message "Sorry, 
you didn't have proper permissions to perform this change."
Well, rights shouldn't be the problem since I'm admin.

The media field from where I access the element browser and the upload 
tab is in a custom extension.

When I do the upload via the backend module (Media => File) indexing 
works fine though.

Any ideas?

Thx
Peter