ahoy all,
i was having same 0% error on shared hosting on fresh install of plugin, checked Error Logs of Apache and saw lots of
[Sat Feb 02 17:55:07 2013] [error] SoftException in Application.cpp:601: Directory "/home/XXXXX/wordpress/wp-content/plugins" is writeable by group
errors while BackWPup was sitting at 0%. when i simply changed the /wordpress/wp-content/plugins to not be group writeable, the plugin started to backup, though currently it never reaches 100% on the “Working” page, but the backup does seem to be complete and correct.
hope this helps.
peace