I recently started using Memcached to store user sessions, and some Firefox and Android users are now reporting being logged out of their accounts intermittently and prematurely. I did some testing and was able to replicate the issue a few times with Firefox 36.0.4 on OS X. I have no idea how this could be browser related, but Chrome and many of my other users are not experiencing problems. Here's my caching configuration in config.php: Code: // Cache $config['cache']['enabled'] = true; $config['cache']['frontend'] = 'Core'; $config['cache']['frontendOptions']['cache_id_prefix'] = 'gtpxf_'; $config['cache']['cacheSessions'] = true; $config['cache']['backend'] = 'memcached'; $config['cache']['backendOptions'] = array( 'compression' => false, 'servers' => array( array( // your memcached server IP /address 'host' => 'localhost', // memcached port 'port' => 11211, ) ) ); Here's my memcached stats...as you can see, there's plenty of memory available: I have also attached my phpinfo page below. One question/point of note...in my config.php, the backend is defined as 'memcached'. I've seen many others here use 'Libmemcached' instead. I don't really understand Libmemcached enough to know why it would be used there, but I believe it is installed with @eva2000's Centminmod (which I've used to set up the server). While troubleshooting, I switched config.php to use 'Libmemcached', but it broke the forums and filled the error logs with the following: Code: ErrorException: Memcached::get(): could not read long value, too big - library/Zend/Cache/Backend/Libmemcached.php:166 I'm not sure what to do next.