swank seems not to be strong enough

[z_axis]

The stumpwm never encounter any problem if not starting swank server.   
However, sometimes stumpwm will exit X if starting swank server as :
(progn
   (defvar *swank-p* nil)
   (defcommand swank () ()
     (setf stumpwm:*top-level-error-action* :break)
     (if *swank-p*
         (message "Swank server already running")
         (progn
             (setf *swank-p* t)
             (message "Starting swank on port 4005")
             ;(ql:quickload :swank)
			(push #p"~/quicklisp/dists/quicklisp/software/slime-20130615-cvs/"  
asdf:*central-registry*)
			(asdf:oos 'asdf:load-op :swank)
			(setf (symbol-value (intern "*log-output*" :swank)) nil)
			(funcall (intern (string '#:create-server) :swank) :port 4005 :style  
:spawn :dont-close t) ; :coding-system "utf-8-unix"
             (echo-string (current-screen) "Starting Swank...Done")
         )))
   (defkey-root "s-l" "swank"))


Regards!