It's quite hard for me to explain, to describe what happens, but here it is: On the first pic (RTCW1.jpg), the light comes from a torch in the upper right corner of the screen, and now look at the "circle" in the center of the screen, it is moving along with the moves of the torch's flame and quite matches the scope of the flame's light. On the 2nd, it may be more obvious (RTCW2.jpg). The black moving line is always on the ground. Unfortunately, I didn't manage on this pic to capture the very same weird effect surrounding the flare produced by the gun, some kind of thin black line moving like a snake biting its own tail in geometrical zigzags. As you may have notice from what I attempted to explain, it has to do with lights rendering, and I don't know which factor/otion causes this. On the hardware side: I have two options in the bios that are greyed: - AGP Fast Write Control [Enabled] -Video Memory Cache Mode [USWC] My specs are as follows: WinXP Pro SP1, Athlon XP 1800+, Tt Volcano 7, ASUS A7V333, 256Mo pc2700, ATI RADEON 7500 (AGP 4X), IBM DTLA 7200RPM 30Go, IBM DTTA 7200RPM 9Go, Toshiba DVD SDM1212 (6x), Sony 420GST (19'', 1600*1200*75Hz), SBLive value, PSU:350w. I hope I gave you all needed details for you to help me. But do not hesitate to ask me some more I could give you. Thank you in advance !