Does anyone know why? The database being used contains Paradox tables.

Here is the query:

SELECT
  BOOK_ID
FROM
  BOOK
WHERE
  LOCATION_ID = 1 AND
  AUTHOR_ID IN (8719, 3929, 5186, 6858, 6845, 9969, 9678, 10771, 10564,
< SNIP > < big list of numbers removed >
7453, 168, 11858, 387, 7446, 7291)

The IN clause is huge, but when I take away the line:
      LOCATION_ID = 1 AND
it works fine.

When I make the list of numbers smaller then it works fine too. Is it just a
limit on the number of values you can put in the IN clause? But why then
does it work with the location line removed?

If you're wondering why I'm doing it like this it is because I found that
using ids, and then a lookup field to find the author names (in this case)
is faster than joining the tables.