Hi krodal,
I saw something wrong (or not ?) in your code : the gyro and accel values are inverted !
An example : when my GY-521 is on a flat surface, the "gyro" values are close to "0", and the "accel" ones are around 1.000-15.000, but if I move the module, the "gyro" values quickly go to 1500 before going back close to "0". during this time, "accel" values increased (or decreased, depending of the dirction I moved the module).
Can you take a look at this please, because your code is to complex for me ^^
thanks,
taz
PS: if my english is bad, that's normal, I'm a young french guy 