This falls into "might be bug, might be WAD, figured I'd try here first". Due to some odd planning choices in my current game, my collection of cargo craft of various sorts is a lot larger than my colonization ships. While my colony ships were on a very long run to dump a load of political dissidents on a x3.12 world out in the boonies, my explorers found a x2.0 world with every single trans-newtonian mineral in decent quantities and accessibility, and only two jumps from my home system. I started sending ships to it loaded with infrastructure and mines and construction factories, so that when PEOPLE got there, they'd have something to do.
Slight problem... I realized, many turns later, that "Total infrastructure" on planet remained at 0. Only after the colonists finally got there did the installations being unloaded from various cargo fleets start to actually appear. A look at the "history" of these ships showed they did, indeed, unload items, but it seems that if the population was 0, they weren't being added, though they were removed from the ship's holds.
