7
I post the solution
i put the code as you said before return true;
in /class/database/mysqldatabase.php
mysql_query('SET character_set_results="utf8"');
mysql_query("SET CHARACTER SET utf8");
mysql_query("SET NAMES 'utf8'");
The database has to be with encoding utf8_unicode_ci
All the tables (text and varchar fields) with utf8_unicode_ci
phpMyAdmin shows right the data
And XOOPS too !!!