WPF XBAP not working: Win 7 x64, VS2012, NET Framework 4.5

Hello,

I've built a very simple XBAP application.  See my XAML at the end of the post.

When I run in the debugger, or just open the xbap in IE9, the page appears but I cannot click the menu items.  I just get an audible "ding".

I've set the project as a full trust ClickOnce application.  My setup is Win 7 x64, VS2012, NET Framework 4.5.  I've seen similar posts stating problems for older frameworks, but I'm using 4.5.

I suspect this is a beloved security "feature" that needs adjusting.  Can someone point me in the right direction and prevent me from wasting hours on this?

Thanks in advance.

XAML:

Pagex:Class="Page1"

xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"

xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"

xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"

xmlns:d="http://schemas.microsoft.com/expression/blend/2008"

mc:Ignorable="d"

Title="Page1">

<Grid>

<MenuHorizontalAlignment="Left">

<MenuItemHeader="Menu 1">

<MenuItemHeader="Menu 2"/>

</MenuItem>

</Menu>

</Grid>

Page>