Hi. Looking at the gametutorials.com tuts, the ones with the camera class, I get stuttering in the camera movement. I don''t know why this doesn''t occur on all systems but I get it on some of the mini-demos too, for example Andreas Hammar''s demo. In gametutorials tuts it can be solved easily by replacing a couple of floats in the Camera class implementation file for doubles. In the helpfunction CalculateFrameRate(): static float frameTime to static double frameTime and float currentTime to double currentTime That did it for me anyway.