Duplicate entry msg

It appears that my instance of Drupal got caught in a loop when a user used the same stock symbol as another user. When I deleted on the msg went away.

message: Duplicate entry 'VWELX' for key 1 query: INSERT INTO stockapi VALUES ('VWELX', 'VANGUARD WELLINGT', 34.56, 0.18, 0, 0, 0, 0, '11/30/2007', '6:03pm', 1196702325) in /home/connkoe1/public_html/includes/database.mysql.inc on line 121.

Severity: error

Drupal version is 4.7
Stock: $Id: stock.module,v 1.17.2.3 2006/11/20 16:47:05 oadaeh Exp $
Stock api: $Id: stockapi.module,v 1.5 2006/07/01 19:37:17 kbahey Exp $