I know this topic is a bit old, but i had the problem of an entry which was present in the menu but not in the wbar.
As this topic is linked on the documentation wiki, I think it could be a good place to give my solution.
I created an entry to connect to a rdp server, but my mistake was, I believe, that I just called it rdesktop, which is also the name of the command to connect my server.
When I realised this, I simply changed the name of my entry (and the icon linked to it) to connect_server, and my entry shown up in the wbar.
So, if you have a script that shows up in the menu, but not in the wbar, just check if its name is not the name of a system command.
Sorry for my poor English...