Block Menu Split issue

On the dev.channelaustin.org site I'm having an issue with Menu Block Split that I cannot resolve after spending a number of hours trying to do so. I think I need help with this.

The Menu Block Split module works fine on Lower Links. If you go to the site, you'll see a link for "Board" in the Lower Links and when you click on that it shows a left hand menu -- the second level menu referred to in the Block as "Menu block split 2nd level."

However, Menu Block Split is not working for the Primary Links. I've compared the way it is set up on the Denver Open Media site (I have access to see that) and it appears that the channelAustin site is set up the same way.

I created a "Get Involved" item for the Primary Links and created two pages that are children of "Get Involved." When I click on "Get Involved" there is no left hand menu and when I use Firebug to inspect it, it shows this

This means the page that is being created is for one-sidebar and only the sidebar-right.

I'm not sure why it is doing this. And I'm not sure exactly how to troubleshoot this. Any help or suggestions are very welcome.