Comment 1 for bug 1327060

Thanks for reporting. It's great that someone is testing the new code with the xfce plugin!

Try changing line 119 in xfce4-dockbarx-plug.py from
self.dockbar.orient = orient
to
self.dockbar.set_orient(orient)

That should fix it, if I'm not mistaken. If it works, could you make a pull request with your changes to github? Tiz said he isn't actively developing the plugin anymore but he gladly merges pull requests.