Have u got the firewall blocking certain ports?
If not here try this then

Launch ZoneAlarm Pro and click the "security" button.
Now goto the yellow side that shows "local" above it and set it to "high" with the slider in the middle.
Now,click the "customize" button. On the top is the high security settings. The only thing that should have a checkmark next to it is "allow broadcast/multicast". UNCHECK the top two above that. That's finished.
Now, scroll down until you get to the medium security settings area. Check mark ALL the boxes all the way down.
Now, when you get to the bottom area, it asks you for ports for TCP and UDP in and out.
Here are the settings to use:
BLOCK INCOMING UDP PORTS: 1-65535
BLOCK OUTGOING UDP PORTS: 1-19, 22-79, 82-7999, 8082-65535
BLOCK INCOMING TCP PORTS: 1-65535
BLOCK OUTGOING TCP PORTS: 1-19, 22-79, 82-7999, 8082-65535You can cut and paste the following above. Okay, this side is finsihed!
Now for the blue side which is "Internet", make sure it has also applied here from the local area. If so, you're prepared! Otherwise MAKE SURE you do the same thing for this side as well!
Now click on the "alerts" button. Okay, now click the "advanced" button.
Here's the fun stuff. The tab local info should be shown. If not, click it.
Now select if you want to show your IP addy, hide it altogether or just hide the last three numbers of the number.
You're hidden if someone breaks into you. MAKE SURE you apply the setting!
The settings above will stop incoming ports 1-65535 and block ALL pings, trojans and more.
Thats all ya need to do.