I think all the quad sinks have a copper "slug" in the middle. The 65nm quad sinks are taller then the 45nm sinks, but they should both have a copper slug in the middle. Here is a pic of them.http://farm3.static.flickr.com/2799/4460998424_dfaea48a6f.jpg
The one of the left is the 45nm quad cooler. If yours is all aluminum then its not good enough.