Connecting to an external database

This isn't related to our software at all, it's more like a general thing. If you call mysql_connect() you must pass the second to last parameter with true, otherwise the MySQL extension of PHP refuses to open a new connection. See http://de1.php.net/manual/en/function.mysql-connect.php for more details.

Anyway, with Community Framework 2.0 we set this parameter to true for our own connection, that should prevent these issues too.

Yes, we didn't use PDO in first place; the early alpha version was a fork of WCF 1.x.