No need to wait for Panther. IChatAV works fine, even behind a Router.
Trash the iChat preferences;
com.apple.iChat.AIM.plist
com.apple.iChat.plist
com.apple.iChat.SubNet.plist
com.apple.iChatAgent.plist
Then trash iChat and download a new copy and install. If you're behind a router, you have to open ports.