When you tested using CanYouSeeMe.org, was there a running service listening on that specific port? If there wasn't then that would account for the result.
Try running another online port probe using ShieldsUP!. Enter the port number in the white box then click on "User Specified Custom Port Probe". If it shows "Closed" then you have indeed setup port forwarding properly but there's no service listening on that port. "Open" indicates that it's open and listening. "Stealth" means it's well and truly closed and your port forwarding hasn't worked.