Thanks... BTW, here's another one...
On this page:
The portion indicating how to create
wp-content/advanced-cache.php provides a unix command to create the symlink:
ln -s plugins/wp-super-cache/wp-cache-phase1.php advanced-cache.php
It doesn't say 'if you're using WordPressMU replace
mu-plugins/, so someone--even if they 'know' they should replace
mu-plugins/wp-super-cache/wp-cache-phase1.php, might forget briefly... ;-)