There are many things that can cause a bad index. See
http://www.craigberntson.com/Articles/kb005.htm for some ideas on what my be causing the corruption.
>Thnaks for your post, and yes i did it, but i need to prevent that, i don't want reindex everytime and lose data because i can have a problem with it.
Craig Berntson
MCSD, Microsoft .Net MVP, Grape City Community Influencer