Hi Mike,

> I note that the Front view appears incorrect whatever the zoom, and the Right view
> is right at some zooms and not others.

I'm not seeing that - over here if I zoom out the front view it shows correctly there:




> Is the 3D view the most reliable (though not 100% so)?

Well this particular bug only happens if you have a curve made up of 4 control points that's being displayed on screen in an exactly symmetrical zig-zag "S" shape. It's more difficult to trigger in the 3D view because due to the angled view and perspective projection there it's less likely to have the exact problem shape in 2D screen space. It doesn't really mean the 3D view is more reliable than the others under normal circumstances.

If you add a point to the curve it should also avoid the glitch as well.

- Michael