First time install of Voxel's firmware and I can't ssh to work.

Hi,
I've installed the latest Voxel build on my R7800 and now I'm trying get SSH to work. I've followed the instruction in Appendix A to gen the
keys and then import the private key in to Putty. When I try to connect to the router I get a "login as:" prompt. I type in "admin" but then I
get a message "server has refused our key", followed by a Putty fatal error window: " Disconnected: No supported authentication methods
available (server sent:public key)"

Any help gratefully received.

Thanks, Nick.