Try adding the other two non COUNT columns to the GROUP BY:
select CURRENT_DATE-1 AS day,
model.name,
attempt.type,
CASE WHEN attempt.result = 0 THEN 0 ELSE 1 END,
count(*)
from attempt attempt, prod_hw_id prod_hw_id, model model
where time >= '2013-11-06 00:00:00'
AND time < '2013-11-07 00:00:00'
AND attempt.hard_id = prod_hw_id.hard_id
AND prod_hw_id.model_id = model.model_id
group by 1,2,3,4
order by model.name, attempt.type, attempt.result;