So its jsut the 32U4 that is the issue. thank you!
No, it's what model main processor chip is being used that determines where the I2C pins are mapped to. The mega2560 and 1280 chips use different I2C pins then the 328p chip (and also the 32U4). The Arduino team has made a change to the shield pin layout on their newest boards (starting with the Leonardo board) to help solve this problem for future main boards and future shield boards by placing two new shield pins adjacent to the Aref pin so that the two I2C signals will be at a fixed location no matter what model main processor chip the board uses. That will not help present controller boards (except for the Leonardo) or present shield modules, but does give a 'fix' going forward.