Hi Dean,
Thanks for posting. Make sure you connect to the router from the internet. You cannot connect from the LAN.
In the router under Firewall-> Basic Settings, Disable Block WAN Request : From the remote location open the Command Prompt and ping the WAN IP address of the router. You should get 4 replies. If not, the router is unreachable.
Make sure that you have the latest version of QuickVPN, 1.4.2.1
Check your Username and Password. If one of these is incorrect you will see "Failed to establish a connection"
Make sure that the Windows Firewall is ENABLED on Windows 7 and Vista PCs.
Disable or uninstall any third party antivirus or firewall software until you get QuickVPN connected. Then configure that software accordingly so it will allow the VPN connection.
Please reply if you have any questions.