I can confirm the issue as well. The graphical glitches become introduced in the Dark Room and stay visible in the Core (as seen in the pictures koszer posted). I can't tell if the screen restores to normal behavior after the Core, because i wasn't able to defeat the Core yet due to the graphical distortion.
It restores to normal if you leave the Dark Room by the front door to the previous room. The difference of these two rooms to all the other rooms before is a somewhat floating waterlayer in front of the screen. The graphic errors are all drawn to the background layer, the layers in between are drawn correctly. So to me it seems like a refreshing error of the background layer due to the additional layer in front of the sceenery, more likely a bug in the game than in powersdl.
Would be nice if someone could fix it, so the Core would become defeatable to me