Well the problem isn't 32bit vs 64bit, instead, it seems to be AMD's newly released Windows 8 Customer Preview drivers. Fortunately, I hadn't formatted the SSD yet, so I stuck it back in to make sure it wasn't a hardware failure, and running on it, everything was back to where I had left it.
The HDD tests fine & with only occasional writes to it, it shouldn't affect folding anyway.
Also eliminated was any potential FAH core problems i.e. new releases not playing well. Before re-starting FAH on the SSD, I deleted both cores so that both the GPU & SMP clients would download new cores (16 for the GPU, A4 for SMP), and they're still running fine.
So this leaves only two differences between the setups:
1> SSD Vs HDD
2> Win 8 default drivers + 12.4 Catalyst video driver Vs AMD Windows 8 Customer Preview drivers for entire system
I then replaced the Windows 8 video drivers with 12.4 Catalyst drivers for Windows 7 32bit, and folding improved on the HDD, but still not up to the level it is on the SSD, so that means another reinstall to HDD with only video card driver updated to 12.4 Catalyst for Win 7, & I should be able to crank out another 6,000 ppd for the next 6 - 8 days when Win 7 Home Premium arrives & is installed, & I start over yet again