I think Gforce85 and you mixed so much things in the DLLs and the PATH of your Windows computer that it's too difficult to help you without being in front of it.
It works now with the windows 64 bit version!:
My installation dir is:
D:\Open Source\Sweet home 3D 27-3-2013\SweetHome3D-4.0-src
And in eclipse at the run configuration menu I have this in the VM arguments: