Payment module, how to register to be able to activate?

Hi,

I just downloaded the Payment module dev kit but I can't get it to be listed in the payment gateway drop down in admin area. I changed all "template_" named functions to "payex_", additionally I set the name to be "payex";


function payex_config() {
$configarray = array(
"FriendlyName" => array("Type" => "System", "Value"=>"payex"),
<etc> ..

The file(s, plural actually, since there's the callback module to) was placed in the modules/gateways and modules/gateway/callbacks respectively, with correct owner and same permissions as all other modules (640).

Am I missing something obvious? As I understand the pdf in the PaymentDevKit I should be able to activate it (and thus, it should be listed).

Thanks,