I conquered a small, initially pre-TN empire located on a single planet (they hadn't quite finished construction of their first ship when I invaded), but due to their missile bases I never got around to doing a geo survey. The colony has handed over to me all their installations and such, but for some reason no mineral survey of the planet they're sitting on (Maybe because they're still 'Conquered'?). No big deal, I figured, I'll jut fire up SM mode and use the F9 'System' window, 'Body Survey' button. I clicked it, but no survey info was provided. Hmm, I thought, maybe mine is not the default empire. After ensuring that it was, I hit the 'Body Survey' button again. Still no information.
Experiment time. I hit 'Star SB Survey' and got info for every body. I hit 'No SB Survey' and it all went away again. I selected my other colony in the same system, and hit 'Body Survey' - it worked fine. I selected the Conquered pop and hit 'Body Survey' - no information. Then I tried 'All SB Survey' (worked), 'No SB Survey' (worked), other colony 'Body Survey' (worked), Conquered pop 'Body Survey' - no information.
Four game-months down the road and the colony is now Occupied: 'Body Survey' - no information. A newly-built geo survey vessel stpped over on its way to join the rest of the fleet and surveyed the planet normally - everything worked just fine, the info is now mine. Ater that I experimented again, setting the system to no survey, then using the the 'Body Survey' button on the (still) Conquered pop and it worked normally.
The only thing I can think of is that it's possible I forgot to have the NPR survey its homeworld for minerals when I set it up, and that the 'no survey information' flag was passed to my empire when I conquered the planet.