OK so, I gave up and installed 2.0.7 c even if I have to change back everything.
Nothing changed on the address/info for the user, not saving the info.
Also, I tried to add the address through backend and this error appeared:
vmError: TableUserinfos::store failed - Duplicate entry '4294967295' for key 1 SQL=INSERT INTO `mo79_virtuemart_userinfos` (`virtuemart_user_id`,`virtuemart_userinfo_id`,`address_type`,`address_type_name`,`name`,`phone_1`,`phone_2`,`address_1`,`city`,`virtuemart_state_id`,`virtuemart_country_id`,`zip`,`agreed`,`created_on`,`created_by`,`modified_on`,`modified_by`,`locked_on`,`locked_by`) VALUES ('88','0','BT','','Melina Ferszt','48110105','','Juncal 1980 4ºB','Buenos Aires','374','10','1125','','2012-05-18 23:26:39','42','2012-05-18 23:26:39','42','0000-00-00 00:00:00','0')
vmError: No se pudieron guardar los datos de usuario.
And when I click on the addST on backend nothing happens so... I cant add the addresses on frontend or backend at all... not one, not mny, nothing....