I found the problem, here it goes:
I was saving special char in the enum type (accent)
field2 ENUM('Administrator', 'Usér', 'Guest');
and when my query was trying to insert Usér it fails. So I changed table definition to this:
field2 ENUM('Administrator', 'Usér', 'Guest'); and now everything is working fine.
Thank you for your responses and time.