I’ve been working on integrating some controls which call in to COM classes in to a Silverlight client. Since my controls use COM, they only work out of browser. The client does have out of browser installation options turned on, and when I launch the client from visual studio, I can right click it, and install it to the desktop. That all seems to be working fine. The strange part though is that my controls don’t work when they’re out of browser – I get an error that the COM server can’t be started.

The stranger part is that if I go in to the clientproperties, and set the Start Action from “Dynamically generate a test page” to “Out of browser application”, my controls work fine, and I get no COM errors. So I guess I don’t understand the difference between installing the application to the desktop through the right click menu and setting the application to start as an out of browser application. Any idea what's going on here?