@proppy: So if you said that the lowest output bit is on GPIO[8], then you're not getting output from channels 8, 9, 10, 11, 13, and 15. This seems like purely an output configuration problem. How have you specified your outputs? What was the calibration result for the device?

re-ran the characterization and got all the output working \o/

This is at 1.6 Volts? What did you change from your previous method?

I didn't change the voltage, I simply regenerated the characterization data