I would be shocked if I was the only one that has ever tried connecting it to a 3.3v Arduino when it should be much simpler.
Connecting a Pi and an arduino through I2C is not the smartest idea on the planet. One reason is that the arduino will have to run in slave mode. This means it can't initiate any communications by itself, it has to wait to be polled by the Pi before it can send data back. Another thing is that you will have to fashion a software interface so the arduino looks like an I2C slave accepting register bytes or code bytes, and then sends the fixed number of bytes back.