FIX: You may receive error 1203 when you run an INSERT statement against a table that has an identity column in SQL Server 2005
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: You may receive error 1203 when you run an INSERT statement against a
table that has an identity column in SQL Server 2005
http://support.microsoft.com/kb/933265/en-US