Index: branches/5.0.x/core/admin_templates/js/uploader/upload_manager.js
===================================================================
diff -u -N -r12395 -r12791
--- branches/5.0.x/core/admin_templates/js/uploader/upload_manager.js	(.../upload_manager.js)	(revision 12395)
+++ branches/5.0.x/core/admin_templates/js/uploader/upload_manager.js	(.../upload_manager.js)	(revision 12791)
@@ -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);
 	}
 }
Index: branches/5.0.x/core/admin_templates/js/uploader/uploader.js
===================================================================
diff -u -N -r12595 -r12791
--- branches/5.0.x/core/admin_templates/js/uploader/uploader.js	(.../uploader.js)	(revision 12595)
+++ branches/5.0.x/core/admin_templates/js/uploader/uploader.js	(.../uploader.js)	(revision 12791)
@@ -364,7 +364,7 @@
 	this._prepareFiles();
 
 	// sync position of all uploaders below current, because file queue height change will not affect their positions
-	UploadsManager.iterate('syncBrowseButton', 0);
+	UploadsManager.iterate('syncBrowseButton', 'timeout:0');
 }
 
 Uploader.prototype.removeFile = function (file) {
@@ -603,7 +603,7 @@
 }
 
 Uploader.prototype.disableBrowse = function($disabled) {
-	if (!isset($disabled)) {
+	if ($disabled === undefined) {
 		$disabled = true;
 	}