The data being sent is the value 0, that looks alright to me though I've literally never used I2CWrite.
Check the pins you're using for multiplexed functions, specifically analog such as ADC and comparators and make sure the pins are set to digital.

Then I'd check the pins with a scope or logic analyzer to verify if data is actually coming out or not - if you don't KNOW, for sure, that the Arduino code is working.

/Henrik.