Working good, so long as I don't count downloading in the equation. Everything says "Queued", regardless of which machines try to download from others. Very odd. There's not that much in settings to go wrong, really.

The central/permanent client is behind NAT, sort of, it's actually in a DMZ of a NAT firewall so it can be reached easily from outside. I was wonder if that was what Export Host IP was for. Doesn't seem to matter if I put the real IP in there or not, still downloads any direction result in 'Queued'.