Iogear USB to VGA adpater slows down Road Hog

I have noticed recently under 3.0.5 that my RH is running way slow when I am using the USB-VGA adapter. The console response is very sluggish on both the UI and the DMX output slows down as well. I can see the data LEDs on my opto really flicker when the adapter is plugged in, and looks normal when I disconnect it.
I'm experiencing things like slow screen redraw, values on screen showing up a full second or two after I change them, and very jerky movements on fixtures with FX running on them.
Related