XP_logininfo

I read about limitations on running the Xp_logininfo in SQL 2005. In fact, from: ms-help://MS.SQLCC.v9/MS.SQLSVR.v9.en/tsqlref9/html/ee7162b5-e11f-4a0e-a09c-1878814dbbbd.htm

I read

Note:
In earlier versions of Microsoft SQL Server, permission to executexp_logininfo can be granted to users. In SQL Server 2005,xp_logininfo can be run only by an administrator. Nevertheless, I made a test and succeeded to grant the rights to a user which is not an administrator, have you any ideas on the reason? Thank you very much