Index: branches/5.1.x/core/admin_templates/js/uploader/upload_manager.js
===================================================================
diff -u -N -r12657 -r13086
--- branches/5.1.x/core/admin_templates/js/uploader/upload_manager.js	(.../upload_manager.js)	(revision 12657)
+++ branches/5.1.x/core/admin_templates/js/uploader/upload_manager.js	(.../upload_manager.js)	(revision 13086)
@@ -67,17 +67,31 @@
 
 UploadsManager.iterate = function($method, $timeout) {
 	var $me = this;
+	var args = Array.prototype.slice.call(arguments); // convert to array
 
-	if (isset($timeout)) {
+	if ($timeout !== undefined) {
+		// 2nd parameter is given
+		if ((Object.prototype.toString.call($timeout) === '[object String]') && $timeout.match(/^timeout:([\d]+)$/)) {
+			// it's string in format "timeout:<number>"
+			$timeout = parseInt(RegExp.$1);
+		}
+		else {
+			// this is not the timeout, but 1st parameter of iteratable method
+			$timeout = undefined;
+		}
+	}
+
+	if ($timeout !== undefined) {
 		// make delayed iteration (helps with direct innerHTML assignments in IE)
-		setTimeout(function() { $me.iterate($method); }, $timeout);
+		args.splice(args.length - 1, 1); // remove timeout
+
+		setTimeout(function() { $me.iterate.apply($me, args); }, $timeout);
 		return ;
 	}
 
-	for (var i in this._Uploaders) {
-		var args = Array.prototype.slice.call(arguments); // convert to array
-		args.splice(0, 1); // remove method name
+	args.splice(0, 1); // remove method name
 
+	for (var i in this._Uploaders) {
 		this._Uploaders[i][$method].apply(this._Uploaders[i], args);
 	}
 }