Comment 9 for bug 318301

I did:

sudo iptables -L

I forgot to paste the output in here before restarting my computer after doing the other two commands you suggested. (oops).

I then ran:

sudo iptables -F

Followed by:

sudo ufw disable

And restarted the computer. This still did not do the trick.

I decided to install firestarter, run it, launch vncviewer from my laptop, and noticed it appear as a blocked event. So I right-clicked on it and told it to allow and I can now VNC into the PC once again. I also ran vncviewer -listen from the PC and then ran x11vnc -connect [my dyndns address] and it worked without any need to make a rule in firestarter. So everything that I need is working once again.