The bug-thread was closed. Ashley replied:
Closing as not a bug: you're just seeing the effect of linear sampling over sub-pixel positions. This is a normal result in computer graphics.
For pixel-perfect display, use the project settings 'Letterbox integer scale', Pixel rounding on, and 'Point' sampling.
I tried those settings but the situation got even worse. after loading the example only vertical lines are shown. and if i move around those vertical lines start to flicker and sometimes disappear completely leaving a blank screen. also when using "Letterbox integer scale" the resolution is a lot smaller.
so my bug ticket was closed and i still have no clue what is going on here...