coopster - 10:46 am on Mar 22, 2013 (gmt 0)
Welcome to WebmasterWorld, AlexMagic.
ADOdb is not a standard PHP extension. I'm not saying that means it is bad or not popular, just that you may find less folks in the forum familiar with it. PDO is standard in PHP >= 5.1 and may be a viable alternative to try as well.
That said, am since I am also unfamiliar with ADOdb, the first place I guess I would look would be the error logs. That is, assuming ADOdb has hooks written in to write to your error logs. And have you tried to var_dump your $conn variable directly after attempting to create the new object?
$conn = &ADONewConnection('oci8');