I have a complicated VS 2010 isolated shell project. In this project I have a form designer which has winforms controls, hosted in wpf using WindowsFormsHost. I also use the VS propertygrid.
When the focus is in the propertygrid and I open the menu using the keyboard, navigation keys work on the propertygrid instead of on the menu - hitting the down arrow causes the selected property to change in the propertygrid, and not the menu item change.
When the focus is in the form designer, a control is selected and I open the menu using the keyboard, navigation keys work both on the menu and on the selected control - hitting the down arrow causes the selected menu item to change, and the control to move in the designer.