When .gtk-bookmarks contains links to samba shares "smb://server/sharename/folder[/] [MyFolder]", the File Browser Launcher instead displays a link to "Network" and launches "smb:///". The behaviour is the same whether the samba shares are present or not. These links also do not work in the awn applet Places, but they do appear correctly (albeit with a folder icon instead of samba icon).
Any bookmark that includes the "MyFolder" part (with or without spaces in the name) will show up correctly and launch in the Gnome Places menu, but the File Browser Launcher will popup the error "Could not find '/path/to/folder[/] MyFolder'."
Running Ibex with latest repository versions (as of Nov 11th, 2008, 0.2.6).
Well...if it doesn't work with a GNOME applet in addition to the Awn applets mentioned, I'm inclined to believe that it's a GNOME and/or Ubuntu problem. I would figure out how to get the samba protocol (smb://) registered. (Although I would imagine that Ubuntu would automatically register it if samba was installed.)