I guys, have just tried utilising the router again and yes I can also access my webpage so port forwarding seems to be working. NAT Loopback is not enabled as previous experienced. Which is what you seem to be experiencing (and myself). I am not an expert on this stuff but NAT Loopback I believe is a 'security feature'.
"NAT loopback... where a machine on the LAN is able to access another machine on the LAN via the external IP address of the LAN/router (with port forwarding set up on the router to direct requests to the appropriate machine on the LAN). Without NAT loopback you must use the internal IP address of the device when on the LAN."
Also I had to change the management port to 8080 so I could utilise http (port 80).
One of the other chaps posted in response to enabling NAT Loopback via the CLI but you would appear to need a fixed IP address from your ISP.
This is what PRThomas posted with regards to NAT Loopback -
In terms of port forwarding 80(HTTP) the port forward will work great externally, however internal clients will not be able to access as NAT Loopback is not enabled. I couldn't find an option in the management pages to enable it, however I found a post on another forum that allowed me to enable it via TELNET (only really suitable if you have a static external IP). This change does NOT survive a reboot so will need to be re-done every time the router is restarted!

Example: (external ip 1.1.1.1, internal network 192.168.1.0/24, webserver 192.168.1.10, router 192.168.1.1)

Connect via SSH (or telnet then type SH) and enter:

iptables -t nat -A PREROUTING -d 1.1.1.1 -m tcp -p tcp --dport 80 -j DNAT --to-destination 192.168.1.10

Repeat for each port you have forwarded.

Then enter the following ONE SNAT rule:

iptables -t nat -A POSTROUTING -d 192.168.1.10 -s 192.168.1.0/24 -j SNAT --to-source 192.168.1.1

Well we are gradually finding what is working and what isn't - thanks for that vtr1rider. As you say, having connected my phone via expensive 2G I can connect to my server sitting in front of it and download emails. That's technology for you! Seems everyone with a dynamic IP address (which must be most people) is going to have a problem with this router then.

According to http://opensimulator.org/wiki/NAT_Loopback_Routers this lists TP link TL R470T+ as having working NAT loopback, so this must be something TP Link are aware of if in fact it is working on that router.

Thanks for that added information. I'm having problems connecting via ssh to my router. It won't let me connect via ssh and when I logon via Telnet then it has a set of predefined commands and menus. How can I get the the sh script?

Here is what I see:

--------------------------------------------------------------------------------
Welcome To Use TP-LINK COMMAND-LINE Interface Model.
--------------------------------------------------------------------------------
TP-LINK(conf)#help
normal mode commands:
clear --- clear screen
exit --- leave to the privious mode
help --- help info
history --- show histroy commands
logout --- logout cli model
config mode commands:
config --- enter config mode
adsl --- config adsl
igmp --- igmp config
wan --- wan config
wlctl --- wireless config
lan --- lan config

TP-LINK(conf)#

Also if I change the local port to 8080 I'm getting this error from the router:

SOAP-ENV:ClientHTTP GET method not implemented

Seems it is impossible to access this router with ssh or do anything worthwhile with telnet (At least with the latest firmware). Although the lack of NAT loopback seems to have been an issue with past TP Link equipment it doesn't seem to be high on their list of priorities to make it available on the 8980, seems strange if it was something they made available before that they should not have built it in the current firmware.
Has anybody managed to find a working solution to this problem yet?

Canadianbill, I had exactly that issue and contacted TP-Link about it. After you set your management page to 8080, reboot your router. Then log into it via 192.168.1.1:8080.

Hi vtr1rider, thanks for that. I reset my router and copied the config over. I will try testing that instead on 8080. I presume that is for local logon. If I'm not using port 80 for any service with my server, then I presume I can leave it as is. I use different ports to connect and not sure if this impacts logon at all.

With the latest firmware it seems like the NAT servers work when accessing from an external source outside one's own home network, but it does make it difficult to check this.

I bought this router today and I'm having the same problem which makes it impossible to edit my own website.
I think it might be going back tomorrow....