I have an instance of the radwindowmanager on a master page and use the following code in the content pages to open various windows
var wnd = window.radopen(path, null);
wnd.setSize(w, h);
wnd.center();
wnd.setActive(true);
wnd.add_close(OnDetailClose);
In IE8, this works fine and the modal windows shows with the gray background as seen in screenshot1IE.png. when I execute the same code in firefox/safari, I get screenshot2FF.png
Any help is greatly appreciated.