Workflow AND role

Hi,

I have a question regarding to the workflow.

When i create a service notification IW51, the system generate a workflow and the user recieve a message to unblock the service notification (using status profile).

When we affect the "SAP_ALL" role to this user. The user unblock the notification ..OK

But, i can't find the appropriate role or the appropriate autorization object to affect to the user. i try, iw51/IW52 the user recieve a message but when he unblock the service notification, there is an error.

Thanks in advance for your help