I am experiencing the same static over USB and am also getting sync errors. It does not matter whether I use the ti as the sound card or Audiophile 2496 or KRK ergo FireWire interface. Would roll back previous release but had other issues with the virusti audio driver and was recommended to wait for OS5 - could not select 128 samples without sound degrading hugely.
Virusti is plugged into own usb hub but problem persists even with no other USB devices plugged into the pc at all.
Cubase 5 x64
Win 7 x64