That's really, really strange. Only thing I can think of is that you have something ancient hiding in your Plugins that's overriding some part of the NAM Controller. Try it with a clean Plugins folder, and then after adding NAM 40 into that clean Plugins folder.
Also, check the version number on your SimCity 4.exe file. It'd be helpful to where you got your copy of SC4: GOG, Steam, Origin, off the original discs, or somewhere else?
-Alex