Dear Feffusers, Thank you all for your attention. The problem was in fact in the first two columns containing non-numerical characters; Athena now reads my data correctly. Thanks Bruce, Norbert and Matt for the valuable tips and suggestions... Mauricio ************************************** Maurício Antonio Pereira da Silva Departamento de Física Grupo de Dinâmica Molecular Universidade Federal de São Carlos - UFSCar Via Washington Luiz, km 235 Vila Monjolinho 13565-905 São Carlos - SP Brasil Tel: +55 (16) 33 51 82 22, ramal 262 Fax: +55 (16) 33 61 48 35 *************************************** --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.745 / Virus Database: 497 - Release Date: 27/8/2004