Accuracy of double precision cos and log on GTX 470? Is GTX 470 as as accurate as GTX260

Is the GTX 470 double precision as accurate as double precision on GTX 260 and if so how do I get it. I have a program that seems more accurate for 260 than 470 same code just recompiled with sm_20 option in Visual Studio 2008. It looks like I am getting single precision. I am using Cuda 3.0 toolkit and build rule 3.014
Mike Zielinski