Office 2010 application menu not playing nicely

Hi

I have an mdi application which uses the ribbon control in 11.1. MDI child windows merge their content on the file menu into the parent. This works perfectly apart from the fact that for some reason, the content is shown but is never highlighted.

I have a recent documents popupmenu on the file menu and when all the other options are disabled, this shows with a nice blue highlight in the nav menu  to show that this menu is selected. This recent document menu is owned by the mdi parent and so works as expected.

My mdi child has some other options which merge quite nicely. The only strange thing is that when dropping down the file menu, the first popupmenu is found as per ms guidelines and its content is displayed in the contentarea, except that the popupmenu does not have an indication in the nav menu that it is highlighted. It should have an indicator that it is selected.

Any ideas?

Thanks

Darren