smb link in browser wont open (xdg-open Error showing url: The specified location is not mounted )

Ubuntu 11.04
I have
alpxp@alpxp-laptop:~$ gconftool-2 --get /desktop/gnome/url-handlers/smb/command
/usr/bin/nautilus %s
but:
alpxp@alpxp-laptop:~$ xdg-open smb://10.55.80.128/Video/
Error showing url: The specified location is not mounted
why is it so?

alpxp@alpxp-laptop:~$ /usr/bin/nautilus smb://10.55.80.128/Video/
works perfect

I figured that this is the problem why my browser does nothing if I click to the smb:// urls

ProblemType: Bug
DistroRelease: Ubuntu 11.04
Package: gnome (not installed)
ProcVersionSignature: Ubuntu 2.6.38-8.42-generic 2.6.38.2
Uname: Linux 2.6.38-8-generic x86_64
Architecture: amd64
Date: Wed May 4 18:03:16 2011
InstallationMedia: Ubuntu 11.04 "Natty Narwhal" - Release amd64 (20110427.1)
ProcEnviron:
 LANGUAGE=en_US:en
 PATH=(custom, user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: meta-gnome2
UpgradeStatus: No upgrade log present (probably fresh install)