I have a linksys router, I have successfully set it up to forward traffic from the outside to my linux box using to my ssh server. I also have a vnc server running on it to which I control it internally. At school they block traffic like 5900 so I cannot access my VNC server using that port. I have tried to use port triggering to accept the connection through port 80 and then forward it to the box on port 5901 (5901 is the port which the server runs on) I have another option called UPnP but im sure thats not it. What could be wrong?

If you can connect via ssh, just run VNC through an SSH tunnel. You want to do that anyways for security reasons since VNC has absolutely no security whatsoever. Have a search here on running vnc over a ssh tunnel as there are a ton of threads on how to set this up.