For anyone who might have the same problem, when upgrading to Max 6 I found that jgraphics_rectangle_draw_fast no longer draws a border when the value is set to 0.5.
I thought my rather large gui object was broken when all of my rectangles suddenly had no border!
Changing the value to 1.0 solved the problem and now my object displays as prettily and the same as it did in Max 5 with a 0.5 value.
Hope this helps anyone else scratching their head over this!
Thanks for your reply.
I was aware that it’s drawing is anti-aliased and remembering back to when I built this external, I do remember being surprised that the 0.5 value gave me the desired visual result. I was merely noting that the same external / code, in the same patch, on the same machine, displays differently with Max6 compared to Max5.