After reading many post, still not be able to fix our problem.
We're already using Hamachi and no one in our team is able to host a campaige that all team member can see, usually one to two person can see it. The only solution we found is by turning off Windows firewall and removing the host's rounter. We've tried to change the require configure in Windows firewall and turning off my router's firewall but no luck. DMZ wouldn't help at all either.
We all have different kind of routers but none of them work. Mine is WRT54G with DD-WRT. Such a pain playing this game cause we'll have to reconnect those wires and the other PC can't go online.
So up to patch 1.04 won't help.