ichat help please

[todany]

I only communicate with 1 person on ichat. We are both 'available' but not in messaging each other. My ichat icon will start to bounce but no message??? Did they start to type something to me and just decide not to send it or maybe they are in conference with another one of their chat buddies??? Any help would be great
Thank you!

 

[Satcomer]

Someone has a Firewall in their computer (you or him/her) or in a router they are using. Consult the Apple Documents "Well known" TCP and UDP ports used by Apple software products & Using iChat with a firewall or NAT router to open ports in a Firewall.