by Gareth J Barnard.
Dear Andres,
I just did a quick test using a development installation (clean install of Moodle 2.2.6 with one course and no content) and was able to:
Upgrading Moodle database from version 2.2.6+ (Build: 20121130) (2011120506.03) to 2.5dev (Build: 20130314) (2013031400.00).
Without any issue.
Cheers,
Gareth