People can't ping my computer... help?

[Inditi]

Ok. I have windows XP Service pack 2 installed. I also have a firewall, which is functional and appears to be working fine. Now, I want to play multiplayer games on GameSpy Arcade. The game i want to play is Stronghold (if it's any help). But, I can't seem to play. It just says "Waiting for host". Now, I had a good look, and i've come across information telling me that it's to do with my firewall. I followed the instructions on how to fix the problem. By opening certain ports it would work. So, I did that. But the problem persisted. So, I then found I had to tell the same information to the Windows XP firewall. So, I did that aswell. Everything looked ok. But, it still didn't work. So, my dad tried to ping me to see if it would help, and I found out he couldn't ping me. So, I pinged myself and it worked fine.

So, we've come to the conclusion that it could be because the system can't ping me to run multiplayer. I've found out that it seems the system has disabled pinging. Can anyone help me?

Thanks in advance.

[mahdiislam]

Try disabling one of the firewalls (Windows or the third-party one) and see what happens.

[Inditi]

I can't disable the main firewall, as it's on use for multiple computers and they need it for security. But, I disabled the Windows firewall and it doesn't help at all.

[mahdiislam]

What third-party firewall are you using?

postscript: sorry about the delay in the response(Yahoo!'s put this forum down as spam on my account)