Versuchs mal damit, hat bei mir funktioniert:
When searched in the code, "DbDirMan cache" all references to database directory manager cache which is a part of the caching system that is used for Domino. Of course the cache system simply stores information so that databases are accessed quicker.
There have been known issues in R5.0.12 where adding the notes.ini parameter:
IOCP_DISABLE_ASYNC_NOTIFICATION=1
is used for those idle users that can't be dropped, which I believe is related to the server cache. I asked my cusomter to add the notes.ini parameter and asked to restart the server. Customer quit seeing the problem. We waited for a week just to make sure tatthe problem did not reappear.
Problem did not reappear and the problem was solve by adding that notes.ini parameter.