I have the following problem: When rotating molecules or volumes the whole computer freezes for a while. Sometimes recover and will freeze again after a few more molecule movements. Sometimes the whole system crash, the blue screen appear and a whole reboot is needed. The problem most likely is graphic card related. I did reported it before and was suggested to change the driver. I did but it did not solve the problem. My system currently is as follow: Chimera 1.2422 Windows XP service pack-2 Dell Precision 530 with Dual Xeon 1.4 GHZ processors and 1 GB RAM Graphic Card: NVDIA Quadro 900 XGL Video BIOS version 4.25.0027.05 ForceWare version: 78.01 Before I had: ForceWare version 91.36 So both of these video driver had problems. I wonder if anybody has experienced something similar and found the right driver. Thanks Hernando