Hi Tom, yeah it's the same thing as in the link Marco posted above, just a display artifact and not any true problem.

The actual surface is fine there, and if you export to a mesh format you can force the export mesh to be refined in those areas by using the "Divide larger than" option in the mesh export dialog.

The realtime display mesh just did not get a lot of triangles in that particular area, that tends to happen with a shape that's fairly large but only shallowly curved. When the display mesher breaks things down by angle deviation, an angle of 10 degrees is kind of noticeable in an area shaped like that.

It's not anything actually wrong, it's just something to ignore. It's not really feasible for the display mesher to do a pixel perfect job like a full render because it's more oriented to do things fast.

- Michael