Have you edited anything locally?
No, I don't edit OJS code.
What process did you follow to upgrade?
For upgrade OJS, I downloaded patch and I followed instructions of http://pkp.sfu.ca/ojs/UPGRADE
What version of PHP are you running on the server?
OS platform Linux
PHP version 5.3.10
Apache version Apache/2.2.22 (Fedora)
Database driver mysql
Database server version 5.5.22
Do we might return to the version that worked well and try a new upgrade?