If you don't care, what are your ambient temps? (in both F and C for others). It may be that the cooler is doing as much as it can in a warm environment. Try to cool the room down if you can. Open a window, or move the pc out of its current spot for a while to see if airflow makes a difference.
It's winter in US (forgive me if your from somewhere else!), and I've shut the heat off to my "computer room". I keep it running boinc, and with a window cracked, it actually keeps the room at a normal temperature. They can crank out the heat during games and what not.
I have a 955 C2, OC'd to 3.8 GHz. So I would imagine my CPU gets slightly hotter than yours. I used to have an arctic cooler freezer pro 7 that worked just fine. they are about 30 bucks on newegg.http://www.newegg.com/Product/Product.aspx?Item=N82E16835186134