humanmade/hm-backup — pull request #44 by owaincuvelier (2013-10-18 16:58:45+00:00)
Title: Fatal error with shell_exec and 'blacklist' functions.

We had a user encounter a WPR-04 error. Upon investigation the user was running the suhosin php module which allows you to 'blacklist' functions. the shell_exec function was blacklisted which kills the process and subsequently fatals the plugin.

http://forum.directadmin.com/showthread.php?t=44750&p=228704#post228704