bizzare bug

Needless to say I, either I am completely missing something here, or  
I found an SML bug.

Here's the code:

   fun keyEvents (display, win) =
       let val event = C.new U__XEvent.typ
           fun getEvent() =
               let val _ = F_XNextEvent.f (display, C.Ptr.|&| event)
                   val etype = C.Get.sint (U__XEvent.f_type event)
                   val keyEvent = (U__XEvent.f_xkey event)
		  val ewin = C.Get.ulong (S_'XKeyEvent.f_window keyEvent)
                   (* key press or release *)
		  val ektype = C.Get.sint (S_'XKeyEvent.f_type keyEvent)
		  val ekstate = C.Get.uint (S_'XKeyEvent.f_state keyEvent)
		  val ekcode = C.Get.uint (S_'XKeyEvent.f_keycode keyEvent)
               in

                   print ("ewin="^Word32.toString(ewin)^
                          " etype="^Int32.toString(etype)^"\n");
                   if etype = XDefs.KeyPress andalso ewin = win then
                       (print ("keyPress type:"^Int32.toString(ektype)^
                               " state:"^Word32.toString(ekstate)^
                               " kcode:"^Word32.toString(ekcode)^
                               "\n");
                        SOME(ektype, ekstate, ekcode))
                   else
                       NONE
               end
           fun loop () =
               let val e = getEvent()
               in
                   case e of
                       SOME(x,y,z) => (C.discard event;
                                   (x,y,z))
                     | NONE => loop()
               end

The problem is this:

If I remove the print statement in  if etype... then ... SOME(..)  
else NONE , the calling routine gets the wrong answers.  As you can  
imagine this is rather impossible to figure it out.  With the print  
statement there it works fine, i.e. I get correct keypress codes, but  
using :

                   if etype = XDefs.KeyPress andalso ewin = win then
                        SOME(ektype, ekstate, ekcode)
                   else
                       NONE

Does not work, in that I get the same answer over and over again.

???

Brian



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