AdWords API Sent this to google but they did not answer

Hi all
I emailed this to google but they just replied with ask the group!
So here I am.

I have been testing adWords API for use in our company. If I pull
back stats for 19th Nov 2005 using the API (using getAdGroupStats with
a date of 2005-11-19T00:00:00z to 2005-11-19T23:59:00z). I get
different number to those displayed when I look at a report of the 19th
in AdWords.

An example is if I look at one of my campaigns in adWords I get,
clicks 64, impr 568, cost £34.12. And in the API I get, clicks 141,
impr 1442, cost £76.12. As you can see the
numbers are very very different!!!

Can you explain to me why this is, and how I can go about getting
accurate data from the adWords API?