owncloud is missing the Class 'DOMDocument' (or parts of php-xml)
webdav is not working in owncloud because ‘DOMDocument’ class is
missing.
Either it’s php-xml that is missing the ‘DOMDocument’ class, or it is
provided by a nother package that should be as a depenency for owncloud.
(from redmine: issue id 1470, created on 2012-11-18, closed on 2012-11-19)