What's about this question?
In SQL 2000 - CharIndex is nondeterministic
http://msdn.microsoft.com/en-us/library/aa214775(SQL.80).aspx
In SQL 2005 - CharIndex is deterministic
http://msdn.microsoft.com/en-us/library/ms178091(SQL.90).aspx
Sorry, but question didn't precise about which version sql server was going.
Please give me my lost point 🙂