I can't help you with directly with your problem, but once you get your firewall disabled, go check out this great utility:
Guarddog firewall utility
I was having a lot of problems with my firewall until I found this utility. It allows you to check off the ports that you want to allow the different parts of your network access to, i.e. Internet, Local (the machine the firewall is installed on) and LAN, and then writes a corresponding set of rules. It gives you a lot of preconfigured port selections, (I believe MySQL is included) and the ability to define your own. This is a well designed program, laid out in a very instructive way.
If you need IP masquerading, you will need to install a companion utility called Guidedog, also available at the same site.