Error something like:
Could not open location 'smb:///winsam/sharename' There was an error launching the default action command associated with this location.Or a browser like cervisia or thunar is being used instead of gnome nautilus.
A fix that works is to add some gconf keys to define the browser for smb uri's:
gconftool-2 --set --type=string /desktop/gnome/url-handlers/smb/command 'nautilus "%s"' gconftool-2 --set --type=bool /desktop/gnome/url-handlers/smb/enabled true gconftool-2 --set --type=bool /desktop/gnome/url-handlers/smb/need-terminal false
from http://forums.gentoo.org/viewtopic-t-703471.html