Controlling seperators when using Actions

I'm just starting out using the Actions capability of the CommandBar and I encountered a problem I haven't figured out how to resolve.

To see what I am referring to, open up the provided Actions Sample project.  On the toolbar, there are several groups with a separator line in between.  For example, there is a "copy" icon followed by a separator line followed by the "bold" icon.  If I go into the Actions control panel and hide the "Bold" action, the "bold" icon on the toolbar disappears as expected.  However, it also takes the separator line with it.  How do I preserve the separator line between icon groups when hiding the first icon in the group?  This also applies to menu items as well.

I'm having the same problem. What do you suggest as a solution to this?