Hum, we are using SubSonic 2.0.3, I don't know if this could change something, we never tested 2.1 right now, but this should work anyway.
It seems like you didn't tell sonic.exe where to go look for your templates. You have to pass it the /templateDirectory argument with the path of your custom template.
It seems like you didn't tell sonic.exe where to go look for your templates. You have to pass it the /templateDirectory argument with the path of your custom template.