I've got the MPU9250 linked with an MSP430 via SPI, and I'm using my own driver because I ended up only needing the accelerometer, and no DMP. Accel FSR is set for +/-2g's, DLPF enabled and set at 5Hz, and a 4Hz sample rate.
The Y and Z axes look great, nice and stable, but the X axis is simply all over the place between -FSR and +FSR. I tried a second test board to make sure we didn't physically stress the primary board out of whack, and the second board exhibits identical symptoms.
The last thing I'm looking into is timing between the internal sampling rate and the ODR, and I'll try setting my MSP to respond to interrupts generated by the MPU9250 rather than pulling data at its own rate.
Tacked on to this, I've requested the MPU9250 Self Test app note from Invensense and haven't gotten any response for 2 weeks, so if anyone could help me out with that as well, I would greatly appreciate it.