Hi Marcin , I will be out of the city for a couple of weeks . I am copying my manager and back up owner for the issue. However I would like to know which server you are using as I tried replicating the issue but was not able to using edirectory server. the debug messages suggest that it is in search but those are not of much help till we replicate the issue . If you require any help back up owner will try to provide you the help based on his priorities. And also in the forum if any body is interested he can take the bug forward working with you .
regards Arpit