[turba] Error: contact does not exist

[Ferdinand Gruber]

After upgrading turba to the newest stable version I cannot edit records
in the turba address book. Turba shows a list of the contacts but after
clicking on a contact I get an error message, that says: The contact
does not exist.

I notice that in the query string, shown in the status panel of the web
browser, there appear two query fields:
http://.../horde/turba/contact.php?source=af5d78436cae4c2af68f73f58c2b9e75&key=64e92eb20d08a752b18c4a954f2444d5
In the MySQL Database I only find a field named "key". What is the field
"source"?
The value of "source" changes on every click on the same link.

... also I cannot create a new address book.

Please help me!

-- 
Ferdinand Gruber