[krbdev.mit.edu #5646] NIM display errors when changing default identity

[Kevin Koch via RT]

When there are multiple identities, changing the default identity via 
the Credential menu or the context (right click) menu doesn't always 
work.

In my case, there are three identities.  Among other errors, when the 
third identity is selected and the credentials menu is used, or the 
context menu is used, the default moves to the first identity.  
Toggling views via F7 F7 doesn't have any effect. 

Repeating the operation always seems to set the default as desired.