See my post and the reply / follow-up in this forum entitled
"z3ta+2 no sound from MOST DSF/Wave Scapes patches, nor from a few patches in other libs".
For whatever reason, at least one of the machines I was having this problem on suddenly fixed itself.
However, as a check I tried installing the 32-bit version and running it under Live 8 - the Arps don't work at all on that version. No sound unless I disable the arpeggiator, in which case there is sound from the patch but no arpeggiation.