My problem is another. It looks like that the child window is not inheriting the template or whatever it is and it sets itself back to a standard Windows window. Problem is however when no such standard window had been planed, maybe you end up with a window without anything around it and making you unable to move or resize it, let alone open it if this was minimized. I have this bug in an editor with a mainframe and another frame for the text file whereby you have the possibility to maximize the test file and it ends up with only one window. I just checked an open source editor and the frame was missing, it froze with everything around it.