I'm working on a upgrading Moodle project from 1.9 to Moodle 2. I upgraded to Moodle 2.2.2 without any problem, and the system worked fine at a quick speed. After upgrading from 2.2.2 to 2.2.3, everything slowed down dramatically, from ~5 seconds page loading to +10-15 seconds. I checked every option and set it to default, yet it's still too slow compared to 2.2.2.
Is there any issue related with this? How can I solve/increase the performance of my site to pre-2.2.2 without having to downgrade?