Comment 7 for bug 883508

...
* Installing daemon:
  Shall I install the marionnet daemon in your runlevels ([y]/n)? n

Why not??? The marionnet-daemon installation is a part of the marionnet installation...
You have now to launch manually
$ /etc/init.d/marionnet-daemon start
each time (as root) before running marionnet as normal user.

Concerning the warning:
...
(marionnet:20590): Gtk-WARNING **: Impossible de trouver le moteur de thème dans module_path : « pixmap »

you can find a solution in this page:
http://forum.ubuntu-fr.org/viewtopic.php?id=92216

Best regards,
Jean-Vincent