This problem may occur if a logon object that is contained in memory is incorrectly removed from an array of logon objects.
Cumulative Patch Information
To resolve this problem, obtain the March 2003 Exchange 2000 Server Post-Service Pack 3 (SP3) Rollup. For additional information, click the following article number to view the article in the Microsoft Knowledge Base:
813840 XGEN: March 2003 Exchange 2000 Server Post-Service Pack 3 Rollup
To resolve this problem, install the Microsoft Exchange 2000 Server Post-Service Pack 3 Messaging Database (MDB) patch. For additional information about how to obtain this update, click the article number below to view the article in the Microsoft Knowledge Base:
329882 XGEN: Post-Exchange 2000 Server Service Pack 3 Messaging Database Fixes That Are Available
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.