3 axis compass calibration

Hello, I have tested HMC5883L example which begin by setting the scale

Constructing new HMC5883L
Setting scale to +/- 1.3 Ga
512
Entered scale was not valid, valid gauss values are: 0.88, 1.3, 1.9, 2.5, 4.0, 4.7, 5.6, 8.1
Setting measurement mode to continous.
Entered scale was not valid, valid gauss values are: 0.88, 1.3, 1.9, 2.5, 4.0, 4.7, 5.6, 8.1
Raw: 264 -48 -472 Scaled: 242.88 -44.16 -434.24 Heading: 6.06 Radians 347.08 Degrees
"

the program says that the scale is not valid
I have added a line to know the numbre error : it is 512
what does it mean?

Thanks for your replies