Enrique,

You have files in the m2 snapshot repo from a deploy which need to have the group rw permissions
added to them here on people.apache.org:

     /www/people.apache.org/repo/m2-snapshot-repository

Please fix this. Make sure you massage permissions on each deployment. 

We need to either fix maven's deploy plugin or make sure we massage permissions after each deploy. 
I think Trustin had a fix for it at some point but I don't think the maven guys incorporated it.

Alex