[Evolution] Free/Busy Retrieval via http (non-groupware) not working

[Ian Schaplowsky <belkin intellivid com>]

In Evolution v.1.4.6 (on SuSE 9.1) I was able to create a contact, 
filling out the Free-Busy URL which points to a .ifb file on a web 
server, invite this contact to a meeting and see his/her free-busy 
display to pick a meeting time.
I have tried several versions since then, the latest being Evolution 
v2.4 on the Ubuntu Breezy Badger PreviewLive CD, and Evolution does not 
fetch free/busy information via http, as verified from the www server 
logs.  The same free/busy url cut and pasted to a browser works fine.

The most recent relevant post on the list I can find is here:

  
http://mail.gnome.org/archives/evolution-list/2005-February/msg00370.html

Has anyone else experienced this?  Maybe the contact free/busy url in 
later Evolution versions needs a different syntax?  Any ideas?

Many thanks,

Ian