Rex file import on 64 bit

I’ve been checking functionality in this area and I can import a Rex file in 32 bit cubase 6.06 fine, but cannot in the 64 bit version. After nosing around I find that there are three different versions of Rex shared library.dll present in various locations, one of them being in the windows system32 folder, and none present in either of the cubase app folders. Also the 64 bit and 32 bit files located in the reason app folders are of differing sizes although they both report the same version number and have the same file name. Any wisdom out there, or is the problem not associated with this file and its various locations.

Win 7 ultimate 64 bit
Cubase 6.06 32 & 64
Reason 6.02 32 & 64