Window Maker bug or feature?

[This is with Window Maker 0.20.3, and I am not familiar with gnustep/nextstep] If I have two XEmacs frames on a virtual desktop, double click on one of the title bars so that only the title bar is showing, I cannot then make the other XEmacs frame go away with `C-x 5 0'. It beeps and says that I am attempting to delete the only visible or uniconified frame. That's not exactly convenient especially since there is the inexplicable lack of a bury window command on the title bar menu. Is a title bar-only window then considered iconified?