1240    Index key evaluation error

     Explanation:  An error occurred during index key calculation.  This
     can also be caused by a corrupted header in the .dbf file can cause
     this.  INDEX ON with an EVAL clause not returning a logical true (.T.)
     will also cause this error.

     Action:  Check the index key to ensure it is not on a logical field.
     Rebuild the .dbf file in the DBU utility, or with DBCREATE(), not COPY
     STRUCTURE, then append records.