hmm... weird problem. :think:

I think it might have to do with the engine itsself. If so, i think the code that determines the backbuffer size, might be wrong. The easiest way to get a backbuffer size, is to take the dimentions of the window, and use them as backbuffer size. This method works but it's not entirly accurate, because a window has borders which are taken into account when you get the window size.

This means that the display-area is not the same size as the backbuffer. The backbuffer is stretched/cropped into the display-area, which might result in some artifacts.

I dont know how the backbuffer-size is determined. I haven't solved this problem myself.

It's just a hint, that might lead you to the sollution

Good luck.