Index: misc/ajax.js
===================================================================
RCS file: /cvs/drupal/drupal/misc/ajax.js,v
retrieving revision 1.6
diff -u -9 -p -r1.6 ajax.js
--- misc/ajax.js	26 Nov 2009 03:05:42 -0000	1.6
+++ misc/ajax.js	26 Nov 2009 20:05:00 -0000
@@ -166,20 +166,20 @@ Drupal.ajax = function (base, element, e
 
     return false;
   });
 
   // If necessary, enable keyboard submission so that AJAX behaviors
   // can be triggered through keyboard input as well as e.g. a mousedown
   // action.
   if (element_settings.keypress) {
     $(element_settings.element).keypress(function (event) {
-      // Detect enter key.
-      if (event.keyCode == 13) {
+      // Detect enter key and space bar.
+      if (event.which == 13 || event.which == 32) {
         $(element_settings.element).trigger(element_settings.event);
         return false;
       }
     });
   }
 };
 
 /**
  * Handler for the form serialization.