Apple Remote Desktop

I recently purchased ARD and everything on LAN is good. I switched to external remote access, addressing the port forwarding on my router and connected with screen sharing. The issue that I have is that my external connection does not recognize the Mac computer, ARD version or OS version. Im connected, but it doesn't know it is a Mac therefore most functions like restart, high resolution viewing, shutdown are all not accessible. Any thoughts on how to get my Mac recognized for full functionality?