smorizio :
with pc you can some time end up using the same irq or memory range of another device. check your mb guild and see what irq that pcvi slot uses if it close to the vidoe slot they may be sharing an irq or with your sata controler. if you have too try turning off your com port and printer port in the bios to free up a few irq.
Thanks much for your reply. I'd have to say I am a TOTAL newbie when I get deeper into this IRQ thing. My MB manual is almost totally useless. There is no guide for IRQ in my 128 page manual. I thought that devices with conflicting IRQs will be identified by an exclamation mark inside a yellow circle. I see no conflicts noted when I view "connections by type" - IRQ's in Device Manager. I thought there were only 0 through 15 IRQ's but I see a lot more than those. In Device Manager I think I am reading correctly that my video GTX460 is using IRQ 16 and my PCI IDE Controllers are using 16 and 19.
My BIOS configuration, which I could change if I knew what I was doing, shows PCI1 IRQ as "Auto" or 3,4,5,7,9,10,11,12,14,15. PCI2 IRQ is also "Auto" or 3,4,5,7,9,10,11,12,14,15. I don't want to dork things up when everything that I need seems to be working. This has me totally confused so I'd better just live with what I have until a time where a problem shows itself to me and leaves me no choice .....