You attend voice conferences in Microsoft Office Communicator 2007 R2. You find that the conversations in the voice conferences use lots of space in the Conversaton History folder in Office Outlook.
This problem occurs because Office Communicator 2007 R2 stores additional XML data for events that are logged in the Conversation History objects. This causes the IPM.Note.Microsoft.Conversation.Voice objects to be much larger than usual.
To fix this problem, apply the following update package:
978564 Description of the cumulative update package for Communicator 2007 R2: April 2010
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.