>>Harry,
>>
>>did you use any UDFs in any of the tags?
>>
>nope. And don't forget -
>the indexing is taking place in a fresh query which is devoid of indexes at this point
>different source tables yield queries with different structures but still the same problem error messages
>these tables and all queries arising from them perform perfectly normally in all other contexts - including frequent use of the indexes. (they include live data being generated by my clients)
>
>Harry

You don't have any "reserved words" used as field names, do you?