To tell the truth, I needed to get my eyes at a very precise distance from the screen to even see the horizontal artifact. I guess age is another kind of filter. ;-)

Cheers,
Bob

On 11/22/12 1:44 PM, Frank Shearar wrote:

This gives a slightly (as in "I can see it with a MagnifierMorph but
otherwise not) cleaner horizontal join, together with your original
nice vertical join: