The tool for data export is Siebel provided 'dataexp'. ODBC is configured to open the siebel local database which is in 'dbf' format (an Anywhere database). The driver version is 8.00.02.4361 provided by iAnywhere Soultions.
When the long datatype value is increased the number of errors (as in original post) is also increasing. I tried incresing the buffer size of ODBC driver to 16,000 beyond this value ODBC is not accepting.