Marketpress register new gateway

Hi all,

I am trying to create a new payment gateway in Marketpress. I have read some discussions regarding how to do this, and am somewhat successful. I am trying to register the USA ePay payment gateway, and do this by replicating the Authorize.net script. This does work, however, changing the plugin name from authorizenet-aim to usa-epay does not work, therefore I am unable to have both Authorize.net and USA ePay at the same time. Not sure what I am missing, but i feel like these plugin names / slug names are registered elsewhere? Thanks for any input.