Why isnt Liberation working for me?

When i try to play with Liberation on I first start steam as admin then I close my antivirus (F-secure) and finally i run Liberation as admin. When I press "play game" it starts MW2, but shuts it down after about 15 secs and i get this message "Unable to communicate with Modern Warfare 2 Liberation module. Please allow network acces and try again". But as I said i turned my AV (which also acts as firewall). The only solution i can think of right now it to forward ports from my router, but i dont know wich ones LIberation needs. Please help me.

EDIT: oops, sorry for posting in the general section, I thaught i was in the help section ^^

1. Allow exception for VAC Chaos to your Firewall or simply disable your
firewall
2. Some anti-viruses target VAC because it communicates with our master server.
Add VAC Chaos to whitelist or just turn off AV when using VAC Chaos.
3. If using Windows 7 disable UAC
4. Restart computer

and if that doesn't work, try this:

1. Navigate to Steam Directory
2. Delete ClientRegistry.blob
3. Restart Steam Client