Why does my query not yield the expected result?

Hi everybody,

I'm a bit lost here on my SQL 2008.

I have two tables: tbl_transaction and tbl_devicehistory (1:n). The relation is described in the first query.

I want to find all entries in tbl_transaction, that don't have a corresponding entity in tbl_devicehistory.

The first query works as expected (and yields the correct results)

SELECT t.*
FROM tbl_transaction t LEFT JOIN tbl_devicehistory h        ON t.id_transaction = h.id_transaction
WHERE h.id_history IS NULL

But the second does not (yields no results at all):

SELECT t.*
FROM tbl_transaction t
WHERE t.id_transaction NOT IN (SELECT DISTINCT(h.id_transaction) FROM tbl_devicehistory h)

Where am I wrong? I know how to get the results, but why is the second query not working?

Cheers,

Sandra