Hi, I've played Dread Lords for quite some time now, and just recently got the Dark Avatar expansion. I've run into a bit of a problem though during my second DA game:

It's relatively early in the game, and I've got about 10 planets under my control. 3 of them are aquatic and one is radioactive. However, I have fully researched both fields, so the planets are green and work at full capacity. The problem is, the radioactive planet had a lot of open spaces, and a lot more opened up after Soil Improvement, so I decided to make it a ship manufacturing planet. But now that all my manufacturing centers and power plant are built, I want to build a starport on the planet, but the game doesn't even have it available. I can build starports on all my other planets, including the aquatic ones, so am I missing something about Radioactive Planets? Or is this a game bug?

EDIT: I might be an idiot, haha.  Alright, I tested a theory on one of my finished games.  Turns out if you build a starport, then upgrade it to something else, you can no longer build a starport on that planet.  Very lame indeed.  That seems to have been the problem on my Radioactive world in my current game: I acquired it through influence, then paved over the computer-built starport before I could figure out what to do with the planet.  Not great foresight on my part, but a pretty unfortunate bug on the game's part.  Is there any way to circumvent this bug or should I start building research labs on top of my factories?

Thanks for any help.