Yes, it is critical that the version of /usr/lib/X11/app-defaults/XScreenSaver actually correspond to the version of XScreenSaver that is installed. I would have thought this to be obvious.
If the file does not exist at all, things *should* work ok, but having an old version there is definitely going to screw everything up. So just install it. Any solution that involves *increasing* rather than *decreasing* the number of packages that comprise XScreenSaver is an asinine solution.
