Dave, for me it worked right from the start and I didn't encounter any problems. I did not put VE.dll or any other dll in the Sibelius VST plugins folder. In the playback devices menu in Sibelius you can tell Sibelius where your VST plugins folder is. So you don't have to duplicate any of your dlls.
Hope that helps.
farmergiles, I can not tell you if your ram optimizer (whatever it is) will be of any use. However we have a RAM optimizer built in our Vienna Instruments, which gets rid of all the samples that are not in use.
Andi
Vienna Symphonic Library