Cisco WAN :: 1921 To Replace Current Router Which Is Constantly Freezing

I have a Cisco 1921 to replace our current router which is constantly freezing. We have a couple inside servers, one is a web server and application server which needs to be RDP'd to by a couple of clients outside of our network. I cannot get this to work no matter what. I know it's not the server's setup as when I plug the network back into the old router, it works just fine.
 
All clients have access to the internet, and I can successfully ping/resolve hosts from both the router and a client computer connected. I cannot, however, rdp using neither our public IP, nor our hostname. The hostname does resolve to our ISP assigned IP, but the server cannot be contacted, leading me to belive this is a NAT issue. [code]