[CentOS] Cacti/snmp question

Hi,

Trying to follow the recipe at 

http://wiki.centos.org/HowTos/Cacti_on_CentOS_4.x

Which has a bit of an update for 5.x, but no joy.

Anyone know what this from Cacti should suggest?

Data Query Debug Information
+ Running data query [9].
+ Found type = '6 '[script query].
+ Found data query XML file at '/var/www/cacti/resource/script_server/host_cpu.xml'
+ XML file parsed ok.
+ Executing script for list of indexes '/usr/bin/php -q /var/www/cacti/scripts/ss_host_cpu.php 127.0.0.1 1 2:161:500:1:10:public:::MD5::DES: index'
+ Executing script query '/usr/bin/php -q /var/www/cacti/scripts/ss_host_cpu.php 127.0.0.1 1 2:161:500:1:10:public:::MD5::DES: query index'
+ Found data query XML file at '/var/www/cacti/resource/script_server/host_cpu.xml'
+ Found data query XML file at '/var/www/cacti/resource/script_server/host_cpu.xml'
+ Found data query XML file at '/var/www/cacti/resource/script_server/host_cpu.xml'

The problem is that's returning no information to Cacti to any of the SNMP queries. 

My whole goal here is to get something working to graph CPU core use on a
handful of systems.

Or is there a better tool than Cacti (or better documented - hopefully in
the form of simple recipe rather than many haphazard - often out-of-date -
pages of RTFM)? Cacti admits to serious security flaws, not that this'll go
on the public net, but I'd be happier to run something safer nontheless.

Thanks,
Whit