anti aliasing

I suspect this is something to do with open gl but why does the antialiasing of my line work become jaggy when I am on any layer other than the top layer .?
And even more clumsy is that anti aliasing turns off as soon as you click the draw behind button. If i am pressing the draw behind button it means i want to draw behind the line work which I now can’t see because anti aliasing has turned off. you get my point .
Regards dean

In the preferences, on the “Advanced” tab, make sure that “Full Scene Antialising” is checked, use this setting with either 2 or 4 samples (depends on graphic card). Additionally you may need to uncheck “Realistic Proview While Drawing” on the same page (especially when using the Draw Behind feature).

nothing changed when i altered my sample from 3 to 4 . It did work to remove the jaggys when i turned off realistic preview but this of course is worse because it paints over your drawing so that you can’t see what you are painting properly . ( but you knew that right ).
Any way I am just pointing out that someday it will be nice as a future feature if your guys can figure out how to solve this . best Dean