We found out, working with another institution, that PHP's APC library (php-pecl-apc) may cause session conflicts when running in CentOS.
It was initially thought that it was related to timezone not configured in php.ini, but it wasn't the case.
We don't know if anyone has run into this yet, couldn't find anything related here.
Just thought people should know...Here's a link about the APC-CentOS issue (haven't read it, just received and forwarded)
The user reported that disabling APC solved the problem.
Ramón Martins Sodoma da Fonseca
Analista em C&T
Coordenação de Tecnologias de Informação
Instituto Brasileiro de Informação em Ciência e Tecnologia - IBICT
Ministério da Ciência e Tecnologia - MCT