These errors usually show up when your project is linking to the wrong library. For example, this will show up if you have both 32bit and 64bit version installed; The compiler will look at (for example) at the 32bit library but try to use the 64bit DLL, causing the error. It can also happen if you tried to install different versions of OpenNI.
So, unfortunately, it will be up to you to try a few things and eventually figure it out, because unless we are physically there, it's pretty hard to really figure out hat's wrong.
My first suggestion is to uninstall everything and start from scratch. Make sure you install only 32-bit or only 64bit libraries (I use 32bit on my 64bit machine for compatibility issues with 3rd party libs, for now) of drivers, OpenNI and Primesense. Then make sure your PATH environment variable points to the right DLL location, and that your OpenNI project link to the correct library file.
hope you fix it, keep us updated!