@Samsterism, the IMU board is setup for I2C by default so trying SPI code will not work UNLESS you have modified the board. Did you?
I also have one of these shields so I will test with the latest firmware. One thing I usually do when I have I2C problems is first check that there are pull-ups on the I2C lines. The IMU board has them so that should be ok. Second, I run an I2C device scanner to make sure the addresses used in the library are actually the correct ones. This also tells me if the device can be "seen" on the bus. You can find some scanner code here:
What are you developing with - web IDE, Particle CLI or DEV? I should be able to test tonight and report my findings. 