Payable - Accounting - View Accounting Lines

 Opening the form View accounting lines and inserting my condition for the query, I cannot have the same result for two times.
If I don't insert a document class, only payment docs are retrieved.
If I insert a document class, the query seems working.
If I again don't insert a document class all the document class are retreived!

Why??

Is the the this doc id with relative patch useful?

Subject: View Accounting Lines Performance Issue (XLAIQACL)
Doc ID: 459650.1 Type:  PROBLEM
Modified Date:  05-OCT-2008 Status:  MODERATED
Patch 6436663

Thanks
Luca