Caching problem. Site only works with cache off
Here is how I do in my local projects, may be it can help you.

I have one main project(local) and four its instances(cloned). Same files, same db structure (I'm using Memcache Storage module).. First time when I've tried to clone and work on them I faced some strange problems, then I found that they were sharing cached data (I was using default memcached instance with 11211 port).. Then I just copied the default memcached.conf file as memcached_1.conf(memcached_2.conf,...) and changed their port as 11212,... in them, restarted all memcached instanes(sudo service memcached restart), and specified those ports to to my cloned projects in their settings.php, that solved my problem..