Tak spróbuj:
$member = \IPS\Member::load( $values[ 'member_id' ] );
$member->tekst = $values['tekst2'];
$member->save();
A na przyszłość:
/**
* Run UPDATE statement and return number of affected rows
*
* @see <a href='http://dev.mysql.com/doc/refman/5.1/en/update.html'>UPDATE Syntax</a>
* @param string|array $table Table Name, or array( Table Name => Identifier )
* @param string|array $set Values to set (keys should be the table columns) or pre-formatted SET clause or \IPS\Db\Select object
* @param mixed $where WHERE clause (see \IPS\Db::compileWhereClause for details)
* @param array $joins Tables to join
* @param int|array|null $limit LIMIT clause (see \IPS\Db::select for details)
* @param int $flags Bitwise flags
* @li \IPS\Db::LOW_PRIORITY Will use LOW_PRIORITY
* @li \IPS\Db::IGNORE Will use IGNORE
* @return int
* @throws \IPS\Db\Exception
*/
public function update( $table, $set, $where='', $joins=array(), $limit=NULL, $flags=0 )
{