I installed the plug-in following the instruction located here http://wordpress.org/extend/plugins/w3-total-cache/installation/ down to the letter but I'm still getting errors. This is a WPMU install with 5 sites using domain mapping. I have activated it on each site however it only created one site specific directory in wp-content: /w3tc-blogA.com/. I was able to follow the instruction in the error message to change the permission of the files in this directory, however each site is telling me to do the same thing in that sites respective directory (eg. Please run chmod 777 /public_html/wp-content/w3tc-blogB.com/pgcache/.htaccess) however these directories don't exist. What am I missing?
(before anyone tells me this should be in the mu forum, I'm posting here because it is a support request for this plugin, and this is where the plugin author directs support requests on his site.)