late to the party, but here's a true story.
Working on a song with the golden ears of one Mr. Danny Danzi.
I use a Superior Preset. Upon first preview Danny says "Those toms at the end are distorted".
I sez no (in my head). After much experimenting I could only hear the distortion when I turned off the (not Toonrack) reverb (UAD EMT 140 IIRC).
After much more research I find that the culprit was the Superior compressor (i.e. turn it off distortion goes away). Problem solved.
Now, here's the bigger problem. I can't tell Toontrack which preset it is because:
a) once you choose the preset you lose all knowledge of which one you chose (and I had experimented with so many I just don't recall which it was)
b) I owned all the Producer Presets at the time* and I was not about to go experiment and find the culprit and I was too lazy to try and manually recreate the whole chain because I delete the entire (Superior) preset and did it "the right way**"
* I no longer buy Producer Presets
** I do it the prescribed Cakewalk Forum way now