Well after spending a few weeks on a problem, I concluded that the mistake did not come from me, but probably from ati drivers. I explain : I have a camera matrix, waiting to be set up in opengl. So I load the matrix as the modelview, then I send to opengl all my lights positions (so my lights are positioned in world space) and then I draw the scene. here is the problem : If I use glLoadMatrix with the camera matrix, then the lighting change with the camera. but ! if I use glLoadIdentity and then glMultMatrix, then the lighting is going the right way. This two methods may obvioulsy return an identical result, but it is not the case; that's why I think of it as a driver problem. May you (people with ati cards) test if that do the same on you computer ? If so, it may be a good idea to send a mail to ati so they can fix it in the next driver. PS : I use 8.14.13 drivers as I did not manage to get the 8.16.20 working. but theres is nothing about something like that in the changelog. thanks in advance. Here are my system specs : OpenGL vendor string: ATI Technologies Inc. OpenGL renderer string: MOBILITY RADEON 9700 Generic OpenGL version string: 1.3.5140 (X4.3.0-8.14.13)