restarting my wm pops up Emacs.xemacs.xemacs window

i'm using 21.2 "Dionysos" and gwm-1.8c (btw, are there any gwm'ers?) whenever i restart gwm while XEmacs is running, an emacs window is popped, as large as the whole screen, the info that gwm gives back says Window: Emacs.xemacs.xemacs＠boffi95 the window accepts no events, and if i kill it, XEmacs dies the above is probably a gwm's problem, but i ask because i'd like to know what changed with respect to 20.4 regarding this area, so that i can be somehow informative when reporting to gwm's mailing list tia gb