FIX: Error messages are logged, and some threads may not sort the data successfully if many threads are displaying a report in SQL Server 2005 Reporting Services
Source: Knowledge Base
Product: Microsoft SQL Server 2005 Reporting Services
Notification Contents: New, All Modifications and Delete
FIX: Error messages are logged, and some threads may not sort the data successfully if many threads are displaying a report in SQL Server 2005 Reporting Services
http://support.microsoft.com/kb/936253/en-US