Umm...
I doubt this is the problem, but there has to be a direct connection between your empire and the AI for a comchannel to exist (ie there has to be an unbroken chain of warppoints between one of your colonies and one of it's colonies). But if you have a com channel with your partner, and he has a com channel with the ai, then there should be an unbroken chain there.
Unless, of coarse, I'm wrong about how this all works....
Edit: Then again, maybe not. If there is a break in the chain of systems, but your partner has colonies on both sides of the division, He can talk to both you and the AI, but you can only talk to your partner. The AI would be unreachable by you.
[ 11 February 2002: Message edited by: dumbluck ]