OpenNebula

It shows the following error message when I try to start one:
[oneadmin@bleum1 one]$ one start
/usr/bin/one: line 112: 16113 Segmentation fault $ONED -f 2>&1
/usr/bin/one: line 112: 16114 Segmentation fault $ONE_SCHEDULER -p $PORT -t 30 -m 300 -d 30 -h 1
oned failed to start
scheduler failed to start
[oneadmin@bleum1 one]$ whoami
oneadmin

The system is 64-bit CentOS release 5.7 (Final), and opennebula rpm package is CentOS-5.5-opennebula-3.0.0-1.x86_64.rpm.

I strictly followed online documentation to install one, except xmlrpc packages. I installed two different version xmlrpc packages, since any one of them doesn't involve all libraries which are needed by opennebula.
[root@bleum1 packages]# rpm -qa|grep -i xmlrpc
xmlrpc-c-1.06.31-4.1
xmlrpc-c-1.16.24-1206.1840.el5

Thanks!
Leon