Have you installed the latest Camera Raw update?
New camera models are added to Camera Raw from time to time, and the Camera Raw 5.x series goes with Photoshop CS4.
The list of supported cameras for the very latest CS5 Camera Raw 6.x plugin is here: http://www.adobe.com/products/photoshop/cameraraw.html
The equivalent list for 5.x is in the ReadMe pdf file for installation. I believe your D3s camera is supported by 5.7.
At some point it may be that Adobe ceases to make the older versions of Camera Raw suppoort new cameras, at which point you'll either have to do an additional conversion to .dng then open with the older Camera Raw, or update to the latest version of Photoshop.
Hope this helps clear things up for you.