Dave's u-Supply issue

[ikrel]

I've setup Dave's u-supply from the schematic and I'm having an issue with the voltage follower for the current sense resistor.

I'm reading a constant 22.9v on the output of the follower (24v supply @ 0A) and only get a a few hundred millivolts difference as I adjust the current from the supply from 0-1.5A. if I probe across the resistor i get exactly what you'd expect(0-1.5v).

I've change the op-amp(LM358) and nothing changed. What could be causing this?