1.5V -> 1.65V don't work on my Winchester, so guess they won't on anyone elses. (They provide ~1.56V)
It failed super-pi and very relaxed settings:
RAM, 252mhz @ 3-4-4-10, 2.95V, 1T
CPU, 252 x 9 = 2268 @ 1.56V (maximum for the board)
So, the CPU isn't the issue, because I've had it...