Thanks for the screen shot, this is just what I was needing. Do you have this posted on a live site anywhere? I would like to try this out on the same page as you are using to see if there is some issue with the page or if it a difference that we are only seeing in the browser.
As a work around in the mean time have you tried using the manage table link at the bottom of the menu? This should allow you to make the same edits, just not from the context menu.