40C doesn't seem tooo high for the i7 950. Another reason I prefer AMD over Intel though as I'm using air cooling and idle at 32C at 4.0GHz on my AMD X6 1090T.
Remember AS5 needs up to 200 hours burn in time before it's doing it's job fully (though this only ever makes a few degrees difference). Maybe try to get yourself some MX-3 paste? I've found it drops temps by a few degrees over AS5.