diff --git a/inc/inc.ClassConversionMgr.php b/inc/inc.ClassConversionMgr.php
index 121e337a4..557f796c8 100644
--- a/inc/inc.ClassConversionMgr.php
+++ b/inc/inc.ClassConversionMgr.php
@@ -33,8 +33,14 @@ class SeedDMS_ConversionMgr {
 	 */
 	public $services;
 
+	/**
+	 * @var $success set to false if conversion failed
+	 */
+	protected $success;
+
 	public function __construct() {
 		$this->services = array();
+		$this->success = true;
 	}
 
 	public function addService($service) {
@@ -54,22 +60,30 @@ class SeedDMS_ConversionMgr {
 	 * Return the service that would be tried first for converting
 	 * the document.
 	 *
-	 * The conversion may not use this service but choose a different
+	 * The conversion manager may not use this service but choose a different
 	 * one when it fails.
 	 */
-	public function getService($from, $to) {
+	public function getService($from, $to) { /* {{{ */
 		if(!empty($this->services[$from][$to]))
 			return end($this->services[$from][$to]);
 		else
 			return null;
-	}
+	} /* }}} */
 
-	public function getServices() {
+	public function getServices() { /* {{{ */
 		return $this->services;
-	}
+	} /* }}} */
+
+	public function wasSuccessful() { /* {{{ */
+		return $this->success;
+	} /* }}} */
 
 	/**
-	 * Convert a file
+	 * Convert a file from one format into another format
+	 *
+	 * This method will try each conversion service until a service
+	 * fails or was successful. If a service succeeds it must not
+	 * return false, null, '' or 0
 	 *
 	 * @param string $file name of file to convert
 	 * @param string $from mimetype of input file
@@ -87,8 +101,10 @@ class SeedDMS_ConversionMgr {
 			for(end($services); key($services)!==null; prev($services)) {
 				$service = current($services);
 				$text = $service->convert($file, $target, $params);
-				if(!$service->wasSuccessful())
+				if(!$service->wasSuccessful()) {
+					$this->success = false;
 					return false;
+				}
 				if($text)
 					return $text;
 			}