[mimp] URL not found (/horde/mimp/sessionID)

[Rick Emery]

I've installed mimp (latest CVS head) and set up composite  
authentication. When I log in, and select "Mobile Mail", I am taken to  
my Inbox. When I select "Menu", I get a "404" error:

"The requested URL  
/horde/mimp/[a-long-string-that-looks-like-a-session-ID] was not found  
on this server."

Do I have something misconfigured?

Thanks in advance,
Rick
-- 
Rick Emery

"When once you have tasted flight, you will forever walk the Earth
  with your eyes turned skyward, for there you have been, and there
  you will always long to return"
                                               -- Leonardo Da Vinci