I'm using your RF820 model and am trying to use it for a program called Medinotes. I setup the VPN tunnel and can see the other end, but when I try to 'sync' it says it cannot find the server. (My end) any thoughts?

Make sure you have the proper packet filter rules at both end of the VPN gateway. Your packet filter rules should have:

LAN - Any - Any - Accept
RemoteLAN - Any - Any - Accept

LAN = local LAN of the VPN tunnel.
RemoteLAN = remote lan of the VPN tunnel