Index: wp-admin/js/common.js
===================================================================
--- wp-admin/js/common.js	(revision 37185)
+++ wp-admin/js/common.js	(working copy)
@@ -900,6 +900,13 @@
 	// Add an ARIA role `button` to elements that behave like UI controls when JavaScript is on.
 	function aria_button_if_js() {
 		$( '.aria-button-if-js' ).attr( 'role', 'button' );
+		$( '.aria-button-if-js' ).keypress( function (e) {
+			var key = e.which;
+			if ( key == 32 ) {
+				this.click();
+				return false;  
+			}
+		});		
 	}
 
 	$( document ).ajaxComplete( function() {