For inexplicable reasons, installing a PNY 9600GT video card together with a Hauppauge HVR-1800 capture card on a Gigabyte P35-DS3R motherboard causes Vista not to be able to resume from ACPI S3 sleep mode.
Other combinations are OK with S3 resume, including P35-DS3R + E-VGA 8600 GT + HVR-1800, P35-DS3R + PNY 9600GT . I even tried on another motherboard, an XFX nForce 750a SLI . No problem there with the same PNY 9600 GT video card and the HVR-1800.
I also own a PNY 9500 GT video card, which I tried. It has the exact same compatibility problem as the PNY 9600 GT video card.
So, I can't really say which of the 3 components - the Gigabyte P35-DS3R motherboard, the PNY 9500/9600GT video card, or the Hauppauge HVR-1800 is most at fault. All I know is that they don't work right together with ACPI S3 resume . This is one of the major problems with PCs today - so much hardware can be installed together, but most of the combinations are never tested.