With Rollup?

Im trying to select data from the db and display it in a datagrid with a datareader... I want part sums and full sum on a field called 'quantity'

My sql looks like this (simplified... cause I have lots of joins)

SELECT part_no, part_qty, warehouse_location, SUM(part_qty ) AS sum_part_qty FROM warehouse GROUP BY part_no, warehouse_location WITH ROLLUP

I should get lots of rows, but I only get 25 rows which are all scrambled with lots of nulls... I think my sql is incorrect somehow


And when I executed a query that returned one row (without GROUP BY and ROLLUP I got 11 rows with lots of nulls and irradicate data...

help?
kind regards
Henrik