>>A corrupt index may be at fault here. Try a REINDEX, or, if your table isn't intricately linked in a database, you could manually delete all your index tags, then recreate them.
>
>The table is not indexed but you appear to be right -- the index was corrupt and the table needed to be reindexed.
>
>Regards.

A table does not need to have an order set for LOCATE to use it, just that there be an expression matching the index.

Glad you found the solution. I agree with many others elsewhere that SCAN is much neater to code, and encourage you to make it your friend.