No, they're not gone, I just can see them.
If you go to my gallery in Artropolis, (Artropolis 131,252,23, but you'll have to walk there from my landing point, which isn't far away), you'll be surrounded by 3 36 prim sculptures, 2 are large, one is small and rotating.
I'll bet you can't see the rotating one, except for the top four prims. If you click on it, you'll see them appear.
Now walk to the top of the stairs to get to the second floor. When you reach the top of the stairs, turn and look at the small sculpture. After a few seconds it will disappear. You'll need to touch it again to make it appear.
Now fly away, backwards so you can see the 2 bigs ones. They too will eventually disappear. If you approach them again, they will reappear.
I've played with Graphics settings and I've had other avatars confirm this behavior.
One of the large sculptures is being exhibited elsewhere, where it too disappears.
This is disturbing, I don't want my sculptures to disappear, especially the miniature.
I'd love to know how to fix this. I'll even pay you! The first person who solves this problem may chose any one of my for sale sculptures and I'll give that to you.
Thanks!
Wake