Late in the game, no new ship icons will show up even though there are new ships ready.
Searching the ships in the colony list will find them. But launching them from here doesn't usually work. The launched ships go back to being unlaunched. Bizzare.
Launcing them from the planet list under the colony button does work.
Restarting the game fixes the problem for a 3-4 turns. I check every turn late in the game to make sure that new ships are coming on line.
I think this is a Vista only problem late in games with lots of ships. Several other people have reported seeing it. I have 3 gigs memory on a fairly new Dell.
No one at Stardock seems to care. I guess it doesn't happen to enough people. I wish I could go back to my old XP machine. It slows down too much in big galaxies.