No, by default it is not activated. Did you have a BSOD and activated it to get better dumps?
I ran some root kit scanners, because someone had said that root kits sometimes hook into ataport.sys, which seemed to be misbehaving. One of them must have switched it on.
You use the 1.0.0 drivers. Maybe this helps. Also try to connect the device to a different USB port which doesn't share IRQs with other devices.
Apparently 1.0.0 is the newest version of rdwm1117.sys – 1.5 refers to an updated control panel only. And the Quadcapture USB port doesn't appear to be sharing an IRQ with anything. Durn.
Having run out of solutions, I'm going to try replacing the Quadcapture with a new unit. It will be very funny (after eight months of troubleshooting) if that turns out to be the problem...