Stuttering, Small freezes and framerate Issues

[dlux]

[...]
When reporting back, please include your system specification with:

OS, Graphics Card, CPU & RAM. Also say what settings you used in the launcher (low, medium or high).

Tested the game as requested (low and medium). It hardly improves the stuttering.

Stuttering is worst in the room with the piano, using the lamp causes slighty more stutter. Moving from the hallway (where the room with the ringing telephone is) to the room with the piano (or vice versa) causes the game to freeze for 1 - 2 seconds.

The game is unjoyable with all the stuttering, I won't play it until it is fixed. I have even tried to run the game with the lowest possible graphics settings @ 1024x1280, but it still stutters and freezes.

OS: Win7 x64
GPU: HD5770, 1 GB (Catalyst 13.10 Beta)
CPU: Phenom II X4 @ 3,2 GHz
RAM: 4 GB