What gives with this? Okay, here's the situation.

I'm playing an absoloutely huge map - five stars, dozens of planets and stuff on each of four stars which were started with one and only one player.

The fifth star is mostly wormholes, a few planets, and a Pirate Base.

I've got the pirates in my sights, so I've got a huge fleet of capital ships ready to rock and roll in on the pirate base, but just one phase jump upstream from the pirate base is a newly-conquered planet.

I decide I want to do this the really easy way, and unload that Novalith cannon I spent so much money researching on the pirates, so I try to build one in this upstream planet.

However, it stops construction at 1%, and the construction frigates move on. I've even canceled all the other queued production in the system, and ordered one ship directly to build the Novalith. It builds to 1%, with 27 health, and then stops constructing. The ship will not build it, no matter how many times I right-click on the Novalith, or even specifically order it to build the thing using the icons from the toolbar.

What gives?!