Well I fixed the issue of it 'thinking' the old dll was still installed.

I deleted the DLL files. I then ran VWD, imported an item and simulated; all it wouldn't do was return the simulated item.

I then closed down VWD, and Studio, and installed the dll files; it works now.

Well... The shader on OOT Katherina hair is only partially copied; some is still Studio. Yes, the original is all IRAY.