emacs and Leopard--no X11 support

Hi, I am able to build emacs under Leopard but not to get it to launch in an X window. At the moment, it only works in the local text/Terminal window. This happens even though X11 is running and otherwise functioning more or less normally. Does emacs support X11 windows the way it did under Tiger? I note that I have been running the old emacs versions that I made under Tiger on an updated Loeopard Mac and it works fine. Thanks, Rob