Watch this Author's files
This works under x64 environment;
Mathematica 7.0 win64, MATLAB win64 7.10, Visual Studio 2008, Vista x64.
You have to use mldev64\include and lib\ml64i3m.lib instead of 32bits one.
Be careful not to use Visual Studio Express edition.
I failed to compile mex at first, as they have no x64 libs.