I don't remember it always being ctrl+shift, i could be wrong i guess. Nice one matey, if i hadn't posted i'd still be ffffing around make things more awkward than they need be.
EDIT: No i don't think it was always this way, as i described in my original post, CTRL + click was to select only a type, shift + click to remove a type. If CTRL+Shift is more inline with how other RTS do it, that's fine, just didn't know the functionality had been changed to work differently (do you recall this ever being in any patchnotes?).