[Zope] Management Screen will not load - manage_workspace

[AdvertisingDept]

Zope 2.5.1 has been working happily for over six months.

Suddenly when I login to localhost:8080/manage
The content frame won't display and the page never finishes loading.

Using Mozilla 1.21 for browser.
Attempting to access any object/manage_workspace yields same - content 
frame never loads.

However, If I access object/manage_main I successfully get the content 
frame.
(without the zope top bar frame and without the navigation frame.)


STUPID_LOG_FILE gives no errors.
     
Has anyone experience with this and how to diagnose?


thanks in advance.