1Pixel issue

[Epixor]

Not sure how to really call it but my problem that has been bugging me since i started customizing my UI is that whenever i work with addons that has a background to it the borders seem to "bug/Skipp?" certain pixels on my screen when i move the frames around. Got a screenie for referral:

http://img338.imageshack.us/img338/9...1817325997.png

So that´s my Grid Lay/out atm and i think u will get a idea where as i want the Health bars to be totally surrounded with a black line. When i move/resize the bars one side might be sorted but another side will "bug/Skipp?" a pixel, very annoying.

Does anyone know how to sort this ?