You should find it works on 32 or 64Bit e.g. it's built as a universal 32 / 64Bit binary. There was a problem with 64Bit in V1.0.0 so make sure you have the latest release, if you have problems on 64Bit please let us know - its most likely easier to fix such problems if you email the support link on the website, at
OverTone DSP rather than trying to diagnose the problem on a forum.