For all those people with problems with the lastest release, I've found a temporal workaround until Daniel fix it:
Go here: http://wordpress.org/extend/plugins/backwpup/developers/
And download 2.1.9 release (the last working one for me. You can choose other if you want).
Then, delete the plugin from your site, then, install it again uploading the 2.1.9 zip file from my computer, created a new job, and works fine.
Don't upgrade until a new release comes, after the problematic (for some people) 2.1.11