I found out that both computers can be disconnected from the network and yet direct connect. (eliminates the issue with the uploads and slots)

Both can browse each other like before and I can actually start an immediate download at my brothers's computer which hangs directly on the cable.

He can not and I strongly suspect that my linksys WRT54GL router is the culprit. Whatever I try up to disabling the firewall and do port forward with static IP addresses, my brother will not be able to download from me. He can see and browse but when trying to download he only gets a message " waiting for more sources"

Magnet link renders the same result.

Talking to some idiot rep in Pakistan for Linksys today, he actually tried to sell me that no free pass through to this one computer can be configured on this router.

Definitely I established now, that Limiewire is not at fault. It is 100% the router. Nevertheless, after 4 days of mickeymousing now, I am so wide open for a new approach and appreciate your thoughts.

PS I successfully was able to RealVNC both ways, meaning I am able to remotely manage his machine and even come back to one of mine behind the same router and manage that one from his side.

Just with Limewire it seems the router blocks the upload.