I've noticed that Management portal somehow manages to allow a single user to be in different namespaces in different tabs in the same application (i.e. Management Portal). I've looked at my Processes, however, and see that all of my processes using MgmtPortal think I'm in %SYS, even though 2 of them are looking at globals in two different namespaces; NamespaceA and NamespaceB.
I can even fool MgmtPortal because the first time I try to look at a global in NamespaceA it thinks I'm in %SYS! After a refresh, however, I can see the global in NamespaceA.