Problem/Motivation
Moving modules into contrib/custom after install doesn't seem to work. According to the documentation, all one has to do if one wants to move modules into a custom or contrib directory structure is mv the directory, and clear the cache. This does not work. In fact uninstalling a module, and installing it in one of these directories doesn't work.
Workaround: truncate the cache_container table manually.
Proposed resolution
Ultimately fix this if it can be fixed, but presently updating the documentation would help alleviate the 'oh crap' feeling of a broken site.