Sometimes when I explore, it will happen that while I can see the surface of a the area I'm newly exploring, the surrounding objects there are not actually shown until I move another unit there to explore further.
Here's an example, this screenshot was taken on 3.7.1 on atibox while playing Japanese on the Conflict map. I'm settling to the bottom left gold spot, which is actually way larger than shown here, and is next to the mountains, which are missing here.
(http://postimg.com/143000/conflict_missing_objects-142425.jpg)
This could be an issue which is specific to my graphics card and its properties (and shortness of resources), but I think I've heard reports from other people about this issue, too. It's surely a minor issue, though, walking to this spot with a worker (or any other unit) can fix it. I think this still occurs on head of trunk.