HI.
This week I found possibly a bug in positioning side of S3D.
Positioning the pins of Geared Heart:
1. I deleted all objects from plate except the pin 1.
2. Done all the repairs one can find in the <Repair> menu.
3. CTRL + D and duplicate 9 times the object.
4. Copied object nº2 (the 3rd one in the list) has flipped triangles, others are ok.
Hope you can replicate this behavior.
Cheers