Ok, 'Problem with' is probably more accurate...
So, err, here's my (latest) problem.
I have two syst resources that represent two versions of the same system. Thus they share almost all the same spob's (all except one, the new one which is supposed to 'appear' as a result of the switch). They're numbers 128 and 129. I have a mission, from a planet in that system, which moves the player from one system to the other, using set expression b4 N129. Visibility test for system 128 is "!b4", test for system 129 is "b4".
I can't think of any reason this wouldn't work, but when the switch takes place, I end up with behavior like that described for having two systems visible at the same time that contain the same spobs. (Spobs are invisible on main screen, though they show up on radar. Cannot be landed up or selected, but NPC ships treat them as normal).
Help?