still having trouble getting "add to fleet" to work

I'm running the demo (still waiting for the postie to deliver the full version) - I tried the suggestion from when I posted previously - I have a fleet that just contains one ship and several other ships (all frigates) within a couple of hex - to move the one I want to join to the same hex as the one that is currently in the fleet but the move to command will move the ship to any hex except the current hex.

I can access the add to fleet window but it doesn't show any ships available to add.

I might be that this doesn't work in the demo but can anyone tell me how to use the fleet commands?

I have checked the manual, the wiki and searched the forum.

thanks in advance...