Hi,
You may need SP1, see http://download.microsoft.com/download/c/7/b/c7b400fa-ff4f-43d3-ada1-8d0ea0e6803e/VFP9SP1_FixList.htm

There are some documented fixes for corruption in VFP9.



>How can I prevent Tables or indexes corruption ?
>Yesterday I was running an application and suddenly, without a reason an index became corrupted. I got no error message but the program stopped.
>I spent quite a quarter of hour to know which was the error.
>How can I prevent this ?
>
>Thank You
>Alessio