New to informix - trouble with simple subquery

Hi,

I'm 2 days old in informix, and am having trouble with what should be a simple subquery. In oracle, mysql, sybase and sql server such queries are perfectly fine.

However, informix (via the odbc driver) tells me the there's something wrong with the syntax. Now, the inner query works just fine by itself, so what gives? (According to the IBM syntax guide, this should work unless I missed something?)

Note that I have tried adding an aliase after the closing parenthesis, but still get syntax error...


SELECT
SUM(incalls) AS total,
(SUM(ivr_calls) - (SUM(connected) + SUM(answered))) AS ivr_calls,
SUM(abandoned) AS abandoned,
(SUM(busycalls) + SUM(disccalls) + SUM(other)) AS other,
SUM(internal_xfer) AS internal_xfer
FROM
(
SELECT
1 AS incalls,
CASE disposition WHEN 1 THEN 1 ELSE 0 END AS connected,
CASE disposition WHEN 2 THEN 1 ELSE 0 END AS answered,
CASE disposition WHEN 3 THEN 1 ELSE 0 END AS abandoned,
CASE disposition WHEN 4 THEN 1 ELSE 0 END AS ivr_calls,
CASE disposition WHEN 5 THEN 1 ELSE 0 END AS busycalls,
CASE disposition WHEN 6 THEN 1 ELSE 0 END AS disccalls,
CASE disposition WHEN 7 THEN 1 ELSE 0 END AS other,
CASE firstvdn WHEN '3003' THEN 0 ELSE 1 END AS internal_xfer
FROM
call_rec
WHERE
row_date = '2/21/2013'
AND dialed_num = '3003'
) a