SFTP servers do not show in nautilus network://

[Gérard Milmeister <gemi bluewin ch>]

I have one desktop computer connected via wired ethernet to a ADSL
modem-router an one laptop connected via wireless to this router. When I
open nautilus network:// on the desktop I can see both the desktop and
the laptop SFTP servers. However on the laptop I don't see either. The
avahi daemon runs on both computers and avahi-resolve -a as well as
avahi-discover show the same output on both computers.
What am I doing wrong?
-- 
Gérard Milmeister
Langackerstrasse 49
CH-8057 Zürich