Anyone here using the I2C DAC DFR0971 with Arduino Pro Micro?

Hello group!

I've recently acquired two of these units: I2C DAC 0-10V DFR0971.

I have confirmed that both work correctly using an Arduino UNO.

I am not having any success with the Pro Micro (Sparkfun). Using a variable benchtop power supply, I set it up for 1Amp at 5VDC. When I hook it up, the voltage sags down to 1.5V, and the supply goes into current control mode - as if there was a short. The DAC product page shows that the power consumption should be less than 4mA.

I've checked my project thoroughly and I cannot find a short.

So my question becomes:
On the Wiki page, I've noticed the Pro-Micro is not listed as tested or working. Has anyone here used this DAC with a Pro-Micro?
 

I am at a loss as to what to try at this point, so any suggestion will be might appreciated!!  I can upload pix if anyone is interested.

Thanks in advance!

Ron

Montreal