R12 - View Output submitted by another User issue

Hi,  One of our users (User A) is unable to view the output (i.e.the View Output button is grayed out) of a report submitted by another User (User C) under a different responsibility. But we have User B, who logins to the same User A' responsibility, who can view the output of the report submitted by User C.  What could be enabling User B to view the output of User C ?

I read the Metalink articles on Role Based configuration and checked our system and it does not appear we have it setup that would enable User B to view the said output.