Hi sgornick,
The message you receive on your Ubuntu's terminal looks like that?

Have read the old JXTA ID = urn:jxta:uuid-59616261646162614A7874615032503385F7B45837864801B457A48A5B1A547E03
NetId(TL)=urn:jxta:uuid-75BE74BBCB414A438AF692B40644712202
And your Collanos doesn't appear anyway?

I don't think there is any problem with AMD64 or primary system, as well.
I've some configurations problems with Collanos 1.1 and Ubuntu 7.04 too (see my post in this board) http://community.collanos.com/index.php/topic,857.0.html
You could try to follow the steps suggested in that post. At least, it worked to me.
I hope it'll help you in some sense!

cheers,
Denis Loubach
Collanos Ambassador - Brazil