Ciao,

In rete ho trovato questa nota :

5. API libraries: As of PHP 5.3, libmysql.dll disappeared from the PHP package! There was instead a built-in replacement called mysqlnd. which contains the mysql, mysqli and PDO APIs. Contrary to earlier suggestions on the MySQL site, there is no mysqlnd download—it's built into PHP 5.3, and as of PHP 5.4 is the default for MySQL.

La mysql_connection è stata deprecata, e dalla 5.5 probabilmente sparirà... passa magari alla mysqli o a pdo.

Ciao
Paolo