Index: /views/mods/mod_rechnungen/invoice_pdf.phtml
===================================================================
--- /views/mods/mod_rechnungen/invoice_pdf.phtml	(revision 8475)
+++ /views/mods/mod_rechnungen/invoice_pdf.phtml	(revision 8476)
@@ -933,5 +933,5 @@
 	$filename = $this->view['filename'].".pdf";
 	
-	ob_end_clean();
+	if (ob_get_contents()) ob_end_clean();
 	
 	if ($this->view['preview']) {