Network Folder Removed from Sidebar if Clicked and Not connected to Network

If I don't connect to the network (at work) and try to click in finder, in the sidebar, to a folder on the network, the folder gets removed from the sidebar. This is not the case if the network folder appears on the dock as a 'stack'.

Is there any way to make these to remain in the sidebar, even if the network resource isn't available. I'm constantly rebuilding my sidebar!