Marmalade is a package.el repository, supported by the Emacs community. It's best known feature is the ability to submit Emacs packages directly via Marmalade's web UI.
(require 'package) (add-to-list 'package-archives '("marmalade" . "http://marmalade-repo.org/packages/")) (package-initialize)
What host are you using? With the admin still under active dpeelovment we haven't been testing far and wide yet (just MAMP, a basic Dreamhost account, and a blank-slate Linode instance) but we plan on adding more hosts to the list to get it working under as many out-of-the-box host installs as possible. As for the problem at hand, check out the RewriteBase command in the .htaccess. That's most likely where you're running into issues if it wasn't set correctly (or if it was set to a symlink directory without +FollowSymlinks working) then you'd run into the problems you're describing