ADM1266 not found on PMBus

I am using three ADM1266 in a design.  These parts are not seen when opening Power Studio.  My setup has VH1 = 12V and VH2 = 0V (just 1 input bus).  These parts have a common I2C bus provided by an external 3.3V and the intradevice I2C bus connected to one of the parts AVDD_CAP.  I see that AVDD_CAP = 3.3V and DVDD_CAP = 1.8V.  Why does Power Studio not detect these parts.  I have a 3rd party I2C master tool that does detect these 3 devices.  I also have the ADM1260 in a different design and Power Studio detects it immediately.  I am using the AD USB-SDP-CABLEZ programming pod.