Not a bug, just hardcoded in-game framerate.
Kinda sucks. I guess there's no way to unlock the framerate?
I remember old PC or ps1 games being locked at ~15fps, but it looked less jerky on CRT screens (or maybe I'm just imagining things).
how about the file named "config.dat" open with notepad++ ?
It's located in folder Deathtrap Dungeon\ASYLUM.
There is a line called "FRAME_LOCK 16"