Well what do you know...

...having reinstalled RapPro with the new installer, IT ALL WORKS!
and now i can appreciate it a bit more. Still think the factory content needs work, but some of the organ and orchestral stack patches are lovely, the latter esp will be great placeholders for a demo track until you can use a better orchestral synth for the finished work. even the largest patches only take a few seconds to load now.
i'm not a big MIDI user (other than my piano as a MIDI controller) so can't comment on the issues raised by others but at least the damn sounds work now.