Evolution request to firefox-1.5.0.10-1.fc6 to show a URL fails

When I click on a URL in Evolution (usually highlighted in blue),
firefox does not show the corresponding web page.  The problem is new
since I upgraded to firefox-1.5.0.10-1.fc6.

Starting Evolution from a shell shows the following interesting log.
(The last message repeats every time I request Evolution to get the URL
displayed.)

        $ evolution
        CalDAV Eplugin starting up ...
        evolution-shell-Message: Killing old version of evolution-data-server...
        ** (evolution:3613): DEBUG: mailto URL command: evolution --component=mail %s
        ** (evolution:3613): DEBUG: mailto URL program: evolution
        libnm_glib_nm_state_cb: dbus returned an error.
          (org.freedesktop.DBus.Error.ServiceUnknown) The name org.freedesktop.NetworkManager was not provided by any .service files
        
        (evolution:3613): evolution-mail-WARNING **: gnome_url_show: There was an error launching the default action command associated with this location.

Has anyone else seen this problem.  Is there a solution other than
reloading the last version of firefox?

Thanks - jon