VNC problems... error 10061

I am having a problem accessing my home computer from work(or anywhere else). At home I have opened up port 5900 and 5800 on my SMC router and have opened up 5900 and 5800 on my Trendmicro firewall and the XP firewall. I have two computers at home that are not networked but go through the same SMC router. I can access the RealVNC server from my other home computer (also able to access it from Java) but I cannot access my home realvnc server from any other computer(not able to access from Java anywhere else either). Any ideas? Why does it work from my other home computer and not from outside computers. Thanks, Lee