Exhibit 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation of our reports included in this Form 10-K, into the Company's previously filed Registration Statements on Forms S-8 -- File Nos. 333-76570, 333-76080, 333-96047, 333-96045 and 333-47422 and Forms S-3 -- File Nos. 333-66088, 333-47532 and 333-32036. ARTHUR ANDERSEN LLP Houston, Texas March 12, 2002