There is more information about the issue at: http://www.sophos.com/en-us/support/knowledgebase/118311.aspx
NWOCA has followed to recommended procedures on the Enterprise Console, as outlined here: http://www.sophos.com/en-us/support/knowledgebase/118328.aspx
- Option 1
Sophos is recommending following this procedure to fix the deleted AutoUpdate files: http://www.sophos.com/en-us/support/knowledgebase/118323.aspx
AutoUpdate Fix - Option 2
NWOCA has found that replacing the AutoUpdate folder on each computer, and running a manual update will download the latest definition files.