New Post: problem adding custom gateway

I need to add a new payment option (for Rembours payment) that is similar to the cheque gateway, but with another status and another mail template.
I tried following the HowToCreatePaymentProvider document and created a class library with a single class that is similar to "GatewayCheque.vb" from the source, but with another status and email template.
I can't get this provider to work with the store however. Adding a gateway entry in encapsulatedproviders.xml still only shows a single payment option and causes an error when clicked. I've also tried adding the new provider to gatewayproviders.xml but since those providers are different, this also causes an error.

Is there a way to get 2 encapsulated providers working simultaneously?

Error when adding multiple gateways in encapsulatedproviders.xml :
"The type initializer for 'NEvoWeb.Modules.NB_Store.ChequeInterface' threw an exception. ---> System.TypeLoadException: Could not load type 'NEvoWeb.Modules.NB_Store.Gateway.GatewayCheque;NEvoWeb.Modules.NB_Store.Gateway.RemboursProvider' from assembly 'NEvoweb.DNN.Modules.NB_Store.GatewayCheque,"

-Kristof