Renaming a document not possible under certain conditions

Noticed in archetype 1.07.06 (hippo 7.8.6) with cms version 2.24.08.

Log into the cms. Create a new newsdocument in myhippoproject/2011/news, name it Test (capital is important here). Save the document.
Then rename the document using the Document / Rename option. Change the name to "Test 2". Click ok. Result: the old name is still shown in the document tree.

Check the hippo:translation nodes in the console for this document. The original was stored as en/Test. The new name is stored as <blank>/Test 2. The old name is still shown in the CMS.

This can also be reproduced by adding one or more space to the name.