ADAU1467 Eeprom Interface Write problem

I'm using an ADAU1467 with self-boot eeprom. Writing to the eeprom via the DSP works no problem, using the same settings as the EVAL board.

However, I'm using a Rotary Encoder for volume, and I want it to save position when turned off, however this doesn't work and it resets to zero. What am I doing wrong?