>>
>>It is time to examine the tables and their indexes. Sounds like one table has an index that is refereing to a variable or another table that is not open at the time.
>
>at the point at which this happens, there are no indexes - its a freshly created query in which I'm building the indexes. Neither is it related, yet, to any other table!
>

Harry,

Look at the tables that the cursor gets its data from for an index key expression problem.