A query that references a nondeterministic user-defined function may run slower in SQL Server 2005 than in SQL Server 2000
The following pages were recently modified.
Source: Knowledge Base
Product: Microsoft SQL Server 2005 Enterprise Edition & SQL Server 2005 Standard Edition
Notification Contents: New and Major Modifications
A query that references a nondeterministic user-defined function may run slower in SQL Server 2005 than in SQL Server 2000
http://support.microsoft.com/kb/952217/en-US