Index: branches/5.1.x/core/admin_templates/incs/close_popup.tpl
===================================================================
diff -u -r12127 -r12657
--- branches/5.1.x/core/admin_templates/incs/close_popup.tpl	(.../close_popup.tpl)	(revision 12127)
+++ branches/5.1.x/core/admin_templates/incs/close_popup.tpl	(.../close_popup.tpl)	(revision 12657)
@@ -7,7 +7,7 @@
 			var $is_debug = <inp2:m_if check="m_ConstOn" name="DBG_REDIRECT">true<inp2:m_else/>false</inp2:m_if>;
 			var $use_popups = <inp2:m_if check="adm_UsePopups">true<inp2:m_else/>false</inp2:m_if>;
 			var $redirect_url = '<inp2:m_t t="dummy" opener="u" m_opener="u" escape="escape"/>';
-			var $modal_windows = <inp2:m_if check="m_GetConfig" name="UseModalWindows">true<inp2:m_else/>false</inp2:m_if>;
+			var $modal_windows = <inp2:m_if check="adm_UsePopups" mode="modal">true<inp2:m_else/>false</inp2:m_if>;
 
 			if ($is_debug) {
 				document.write('<a href="#" onclick="proceed_redirect()">' + $redirect_url.replace('%5C', '\\') + '</a>');
@@ -103,7 +103,10 @@
 			function window_close($close_callback) {
 				// use this instead of "window.close();"
 				if (!$modal_windows) {
-					if (getFrame('main').$.isFunction($close_callback)) {
+					// don't use other (e.g. parent) window methods to detect type of
+					// variables from given window, because it won't work in IE
+
+					if (Object.prototype.toString.call($close_callback) === '[object Function]') {
 						// use close callback, because iframe will be removed later in this method
 						$close_callback();
 					}