Question : Problem: What caused garbled/corrupt video after Windows loads unless I disable ATI and use onboard video?

What caused garbled/corrupt video after Windows loads unless I disable ATI and use onboard video? It happened all-of-a-sudden, sitting running. It went to "sleep" and wouldn't "wake" without hard reboot, after which the video was garbled and unintelligible unless booting into Safe Mode or VGA Mode and until I disabled the ATI engine and have to rely on the basic motherboard VGA video. Did not try external monitor since laptop LCD works fine in standard VGA mode. The only associable event was loading X-10 Home Automation software and interface drivers, which I had done on an HP Desk and a Dell Laptop before without problems - the HA downloaded to its USB Interface before the crash and works fine,

Answer : Problem: What caused garbled/corrupt video after Windows loads unless I disable ATI and use onboard video?

Try a newer driver from Omega. This seems to be more of a software/driver issue not a bad video card.
http://www.omegadrivers.net/ati.php