The temp 'copy' I mentioned above is actually an unpacked extraction of a completely different setup exe, not the one I created. It contains multiple identifiable exes within it, including 2 of 64 bits, a copy of MS's shfolder.dll (licensing violation?), some sort of registration dll, plus all sorts of other Delphi crap.
-pillbug
That is the way Inno Setup 5 works, indeed. Not widely documented though.
NB: The shfolder.dll is no licensing violation, but (AFAIK) an allowed/supported way of (easily) supporting known Windows folders for older Windows releases. If it wasn't allowed it wouldn't have been there in the first place.