Using Snortcenter on Red Hat 7.3

I have a Red Hat 7.3 box configured to be my Snort sensor. The following software is being run on this machine:

Bastille Linux
IPTables
FreeS/WAN
Nessus

I just installed the Snortcenter agent on this machine, but it refuses to accept any connections from the Snortcenter server or even locally using port 2525. I have changed the ports numerous times and still no joy. I have even switched off the firewall and still no results. Can anyone tell me what the problem is?