I just installed Wordpress and activated the WP-Cache and the default install will give blank pages on new posts, categories, etc. I found a fix that seems to be working in case anyone else is having the problem.
You need to manually edit the wp-cache-phase2.php file via FTP, located in your wp-content/plugins/wp-cache folder.
Look on line 219 and it should say:
Change that line to:
Upload and it should fix the problem. In my opinion, Dreamhost should fix this when Wordpress is installed...since they say "Please..PLease...Please... install WP-Cache"!