well...I'm not sure...I'm kind of chasing gremlins...but since I added the VT Bass to my pedal board...I am getting distortion and breakup (and not the good kind) when using my active Basses, and even when the pedal is "off"...I started trouble shooting by first checking cables, Then I noticed that on my Voodoo PP2+, the sag pots had been bumped and were turned way down. I thought that may have been the problem (I was starving a couple of pedals and that was causing it)...but after fixing that, I still had the prob....then I started half-splitting the board down until I isolated it to the VT Bass pedal...with the VT out of the picture, it seems to have cleared up.
I have an important gig this weekend and was going to use it, but not I'm gun shy...
I was getting the same issue with both a Spector and a G&L active Bass, but the problem was much more pronounced with the G&L...