Hey,
It seems to me that the file vhzprof.h of DMC library V3x and V4 is the error:

# define VHZ_PROF_MACRO (v) \
/ * Take absolute frequency to allow the operation of Both rotational directions * / \
     v.AbsFreq = labs (v.Freq);

For the float math labs() are not working correctly. Should not be there:

v.AbsFreq = _IQabs (v.Freq)?

which float math will be changed to function: fabs ().

Thanks.
Michael