Andy,
you can call niRFSA_GetError function to obtain the additional, helpful, error information. The error code you are getting is the 0xbffa4001, or NIRFSA_ERROR_NISCOPE_ERROR. This indicates the error from a digitizer. Obtaining the additional error description (create a buffer with at least 2K, e.g. char buffer[2048];, and pass it to the GetError function) will help you and us to better assist you.
Best regards,