Silverlight 3: HTML dropdown menus fall behind Silverlight
If when you hover over the dropdown menus in your website and find that they are disappearing behind your Silverlight media elements in the page making it impossible to click on the hidden menu items, there is a simple solution. You need to activate the ‘windowless’ mode for all Silverlight media elements which are within reach of your dropdowns.
To do this just add the following parameter to your object markup for the Silverlight element.
Your object markup should now look something like this:
Source: schleichermann.wordpress.com
