PlusTrace not getting enabled

[Sanjay Kumar]

Hi,   I ran the Plustrace.sql as user System. Then I granted that role to user Scott. After I log in as User Scott and try to set the autotrace on, it gives me a error   SP2-0618: Cannot find the Session Identifier.  Check PLUSTRACE role is enabled SP2-0611: Error enabling STATISTICS report   Where did I go wrong?   Help appreciated.   Sanjay