Fixes #3355 Can you please test to apply this patch and confirm if it fixes the issue for you?

git-svn-id: http://dev.piwik.org/svn/trunk@6957 59fd770c-687e-43c8-a1e3-f5a4ff64c105

plugins/PDFReports/API.php

@@ -378,6 +378,7 @@ class Piwik_PDFReports_API
 
 					// when a view/admin user created a report, workaround the fact that "Super User"
 					// is enforced in Scheduled tasks, and ensure Multisites.getAll only return the websites that this user can access
+					$userLogin = $report['login'];
 					if(!empty($userLogin)
 						&& $userLogin != Piwik_Config::getInstance()->superuser['login'])
 					{