Multiplayer help....

I apologize if this has already been posted, but I am new to FS multiplayer and have run into a problem.
A buddy of mine just got high speed internet and he wanted us to fly together on multiplayer. I did some reading up on it and realized that I could host a match and he could join it. That was perfect since he and I probably wouldn't fly very well with people on a server who were trying to be professional....Neither or us are too great.
Anyways....I hosted a match 2 or 3 times and we flew together fine. After about the 3rd time, he could no longer search my ip address for an open room. I decided to let him host a match, and I was able to join up once or twice perfectly. Now, neither he nor I can host or join one another's room. If we search one another's ip address, we get nothing; where normally we would find the room perfectly. We have not changed anything on our computers or in FS2004...mainly because we wouldn't know how to, so it isn't like we goofed with a special setting. It worked one day....then it didn't.
Obviously the initial settings on my copy of FS2004 and his copy were fine because it worked well for 3 or 4 times, then nothing..
Any ideas?
Your help would be greatly appreciated.
A buddy of mine just got high speed internet and he wanted us to fly together on multiplayer. I did some reading up on it and realized that I could host a match and he could join it. That was perfect since he and I probably wouldn't fly very well with people on a server who were trying to be professional....Neither or us are too great.
Anyways....I hosted a match 2 or 3 times and we flew together fine. After about the 3rd time, he could no longer search my ip address for an open room. I decided to let him host a match, and I was able to join up once or twice perfectly. Now, neither he nor I can host or join one another's room. If we search one another's ip address, we get nothing; where normally we would find the room perfectly. We have not changed anything on our computers or in FS2004...mainly because we wouldn't know how to, so it isn't like we goofed with a special setting. It worked one day....then it didn't.
Obviously the initial settings on my copy of FS2004 and his copy were fine because it worked well for 3 or 4 times, then nothing..
Any ideas?
Your help would be greatly appreciated.