[otrs] OTRS on CentOS 4.4 incredibly slow

My OTRS system is taking upwards of 20 seconds per action to load pages, log in, process actions etc. This is very frustrating. Could it be the OS that is causing this? I have a standard CentOS 4.4 server load that I have run yum update on, set up mysql and apache, installed OTRS rpm, and basically that's it. I saw a post from someone referring to a CGI update, which I did, then it killed the system and apache would not restart, so I have wiped the system and started from scratch. Mike