When i create any field and want save them, i can´t

I´ve always time this error:


Error

Guardar falló con el error siguiente: SQL=SELECT `t`.`id` FROM `ylq9b_tags` AS t INNER JOIN `ylq9b_contentitem_tag_map` AS m ON `m`.`tag_id` = `t`.`id` AND `m`.`type_alias` = 'com_contact.contact' AND `m`.`content_item_id` IN ( 1)

if i close and come back, all field are empty and form in public site (of course) is empty.

I try several things, but always time this message.

Joomla 3.1.5 installed.

PD: is a great component, beautiful interface and very useful pleasure.