No such problem here either, actually all of my banks presets are usually set at 127, unless they get too loud compared to the other presets... but even when at 127, these do not distort, they just sound loud... in fact I'd have liked the output to be a little bit hotter than it actually is, since many sounds end up being a bit lower in volume, compared to my other synths.
Could it be, that you are actually distorting the REV2 output on your soundcard's input? ... that would certainly explain why it goes away when you dial back on the volume parameter. Maybe your soundcards input are configured for consumer levels and not pro audio levels (+4dB) ?
With that said, some presets certainly can distort, and i believe that is even mentioned in the manual, especially with high resonances... sometimes the FX engine can also distort if the sound is too loud, but it's very rare that I've run into this.
And another thing; have you successfully calibrated your REV2? ... it might be worth a shot calibrating it from the global menu... just remember to let the REV2 warm up for about an hour before you perform the calibration so that it is calibrated at working temperature.