The 2 most probable reasons for such behavior are:
- the links in page C are set with target="_top" which forces the browser to load them as topmost, e.g. not in the IFRAME container (RadWindow is an IFRAME) but directly in the browser.
- There is a "frame buster" script on page D that makes sure that the page will always be opened as topmost in the browser. Here is a sample of such "frame buster":
|if (window != window.top) window.top.location.href = window.location.href;
I am afraid however that there is no workaround for this since you don't have control over pages C and D - otherwise it would be a major security hole.
the Telerik team