'execute stored procedure' is unauthorized

["Stanley Mok" <webforumsuser@xxxxxxxxxxxxxx>]

I have a SP with only an UPDATE SQL, I can execute it in the Query Analyser.  
Yet ColdFusion returns "'execute stored procedure' is unauthorized" error when 
only "execute SP" is checked in the CF Administrator, but works if the "update" 
is also checked.  For safety reasons, my company only allows "select" and 
"execute SP".  Can anybody explain this and help?  It is running ColdFusion 5 
on IIS 6 and MSSQL 2005.

 Thanks.

 Stanley