FIX: Error message when you run a query that fires an INSTEAD OF trigger in SQL Server 2005 Service Pack 2: "Internal Query Processor Error The query processor could not produce a query plan"
Source: Knowledge Base
Product: Microsoft SQL Server 2005 Enterprise Edition, SQL Server 2005 Standard Edition & SQL Server 2005 Enterprise X64 Edition
Notification Contents: New and Major Modifications
FIX: Error message when you run a query that fires an INSTEAD OF trigger in SQL Server 2005 Service Pack 2: "Internal Query Processor Error The query processor could not produce a query plan"
http://support.microsoft.com/kb/939562/en-US