Microsoft has released a hotfix for a problem in which distributed queries using a linked server might incorrectly use the SQL Server startup account to connect to the linked server instead of using the configured linked server account. This problem might occur when both of the following conditions exist:

   - SQL Server is running in fiber mode (i.e., the sp_configure stored procedure lightweight pooling option is set to 1).

   - The distributed query is executed by a Windows NT login and the linked server security is configured to use the login's current security context option.

 

To read more about this problem and obtain the fix, see the Microsoft article "FIX: Distributed Queries May Incorrectly Use SQL Server Startup Account Permissions When SQL Server is Running in Fiber Mode" at http://support.microsoft.com/?kbid=830382 .