Hi Burr, actually it looks like it is dependent on the "Display hidden lines" option being on or off under the View palette:



I had that turned on, that's probably why it was behaving differently for me.

If you turn it on, does it then work ok for you?

I think there is something that needs tuning up though, probably the edges are overwriting the curve when they should instead be skipped because their parent object has selection lock on it. Selection is such a complex mechanism...

- Michael