Minecraft Server vs Technicolor TG582n

[#1]

Hi guys,
I have tried setting up the Game ports in the "Game & Application Sharing" section and have correctly routed it to the PC that the server is running on. I can access the sever over the LAN but for some reason port 25565 just won't open up.
In fact, when I try and check what ports are open, when using an external web service to check, apparently none of my ports are open at all. 😕
The firewall is set to standard so it's not blocking anything. UPNP is activated fine, so I'm a little stumped.
Any ideas?

[#2]

No other Minecraft geeks out there able to offer advice? 

[#3]

Hi there,
If you check the router's settings, are the ports/IPs still bound when you go back to the relevant page?

[#4]

They are are yes. I can connect to port 80 via telnet not problem, but 25565 just doesn't happen.

[#5]

Ok, I just did a wipe of the router to make sure it wasn't anything I had done. Set everything up again, while the port is still marked as closed, people can access the server! Very weird, but at least it works!!