copy and paste between two xemacs processes on Debian gnome

Hi all, I just installed a fresh copy of Debian Sarge and am running
xemacs-21.4.15-gnome-mule.  I have two xemacs frames open editing two
different files.  I would like to select some text with my mouse in one
frame, click copy, and go to the other xemacs frame to paste by pressing
Ctrl-Y or clicking Paste.  Unfortunately, when I try to do this, I get:

Kill ring is empty
or
there is no clipboard selection

Xemacs documentation on the kill ring says:
If you have two separate Emacs processes, you cannot use the kill ring to
move text. If you are using XEmacs under X, however, you can use the X
selection mechanism to move text from one to another.

I searched for "X selection mechanism" and got a lot of results.  Anyone
know how I can simply copy and paste between two xemacs frames ?  I
remember I was able to copy and paste before between two xemacs frames.
Right now to get around this Chinese wall between the two xemacs frames I
have to open gnome's text editor gedit, copy my text from one xemacs frame,
paste into gedit, then copy the text in gedit and paste into my other
xemacs frame.

p.s.  I subscribed to the Xemacs mailing list but I am still awaiting the
confirmation email, so please reply to me.