I found the same thing when exploring the map by planning eyeballs and sending my imps out to build them. Now I explore using bats and ravens instead. There is a problem with sending out large numbers of imps around the map in the late game.
Keeperman,
Now that you mention it, I had also designated eyeballs way out there. I can't remember if that was also happening at the time I claimed items, but it is very possible that's the case.
I probably do have a save game which demonstrates this since, after restarting the game and rebooting the system, I then copied the save game to a new install.
Michal,
I'll try to find a problem save file later today and email it to you.
