Here’s a patch that fixes the issue:
Index: Cdn_Plugin.php
===================================================================
--- Cdn_Plugin.php (revision 1946871)
+++ Cdn_Plugin.php (working copy)
@@ -777,7 +777,7 @@
private $_regexps = array();
private $_placeholders = array();
private $_config;
- private $_replaced_urls;
+ private $_replaced_urls = array();
/**
* If background uploading already scheduled
*
Would love to see this fixed as well.