complex auto correlation using MKL

I am trying to use MKL for autocorrelation of complex vectors XX:

        complex(kind=4),allocatable,dimension(:) :: XX, CXX

        COMPLEX(kind=4),allocatable,dimension(:) :: CRXX

         .......

        !     Do the 1 dimensional complex autocorrelation.
        status = vslccorrnewtask1d(task, VSL_CORR_MODE_FFT, NZONE, NZONE, NZONE)
        status = vslccorrexec1d(task, XX, 1, XX, 1, CRXX, 1)

I have a very naive implementation of auto correlation with complex numbers which I used to verify the result of MKL's implementation. And it suggest that the result is incorrect. The only way I can make it work is to pass conjugate of XX instead of XX as the second input vector. This doesn't make too much sense to me and also the result seems to be scaled by 2.

Appreciate if some one can point out what I have done wrong in the above code and how can I get correct result?

Regards,