Did you check for data corruption in the table?

>I have client with a large table (well, sort of: it is about 20 Mb) in a distributed Foxpro 2.6 exe. For some reason, we are unable to reindex this file. We are using a CDX index that has 4 tags. We originally tried to use the REINDEX command, but it would sometimes give us an "Internal Consistency Error". Now we are deleting the cdx file and recreating it, however we still sometimes get this error. It doesn't happen every time, and typically only happens after the client has been in the software doing things for a while and then tries to re-index. It is easily recreatable, however. Any ideas why we would see this error?