Cannot create diagrams in Upgraded SQL Server 2000 Database

Dear all,

I am trying to save a newly created diagram in SQL Server 2005 SP1.

The error message is:
-Beginning of pasted error message

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Cannot insert the value NULL into column 'diagram_id', table 'adt_db.dbo.sysdiagrams'; column does not allow nulls. INSERT fails.
The statement has been terminated.
The 'sp_creatediagram' procedure attempted to return a status of NULL, which is not allowed. A status of 0 will be returned instead. (.Net SqlClient Data Provider)

Program Location:

at Microsoft.VisualStudio.DataTools.Interop.IDTDocTool.Save(Object dsRef, String path, Boolean okToOverwrite)
at Microsoft.SqlServer.Management.UI.VSIntegration.Editors.DatabaseDesignerNode.Save(VSSAVEFLAGS dwSave, String strSilentSaveAsName, IVsUIShell pIVsUIShell, IntPtr punkDocDataIntPtr, String& strMkDocumentNew, Int32& pfCanceled)

-End of pasted error message

The database I use has been upgraded from SQL Server 2000.

I am running in SQL Server 2000 Compatibility Mode (80) but changing the compatibility mode to SQL Server 2050 (90) does not make any difference with regards to this error.I solved the problem by deleting the table dbo.sysdiagrams and letting SQL Server 2005 re-create it. Apparently, its schema was different.|||

????CONGRATULATIONS!!!!

And thank you very, very much. I had desesperated to resolve this problem with my diagram of forty three tables, that i think that i don′t save it, but you resolve my problem with a simple solution, the eternal "restart", or recreate the table in this case.

Thank you very much another time,

Zapa