Sorry for the delay. We've started out using the BringToFront of RadWindow but it didn't solve our problem. Note that when we're trying to bring to front it means on top of windows of other applications (such as a browser, Outlook, etc.). The solution above is the only thing that worked for us (notice we're controlling the real WPF Window, not the Telerik one).
We could shed any more light on this if you require.