Error posting FICA document using BAPI BAPI_CTRACDOCUMENT_CREATE

Hi,

I am trying to post FI CA documents using a BAPI but getting error 'Balance in Document currency is not zero, posting not possible'.

Do you know why we are getting this error?

* call BAPI

  CALL FUNCTION 'BAPI_CTRACDOCUMENT_CREATE'
    EXPORTING

      testrun          = testrun
      documentheader   = documentheader
      completedocument = 'X' "create documents, calling all events
    IMPORTING
      documentnumber   = ev_opbel
      return           = lv_return
    TABLES
      partnerpositions = partnerpositions[]. "lt_pos_info.
*      genledgerpositions = lt_gl_info.

Thanks

Govind