Cacti not graphing mURLin data

Hi list,

We are facing a problem in which Cacti does not represent the data collected by the mURLin plugin.

We are using Cacti version 0.8.8b and mURLin version 0.2.2.

This is the output from /var/www/cacti/log/cacti.log:
02/17/2014 02:00:11 PM - CMDPHP: Poller[0] Host[60] DS[457] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[458] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[459] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[459] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[460] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[460] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[461] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[461] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[462] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:12 PM - CMDPHP: Poller[0] Host[60] DS[462] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:13 PM - CMDPHP: Poller[0] Host[60] DS[463] WARNING: Result from CMD not valid.  Partial Result: U
02/17/2014 02:00:13 PM - CMDPHP: Poller[0] Host[60] DS[463] WARNING: Result from CMD not valid.  Partial Result: U

If running the script manually from the command-line as the poller user, it returns the correct output:
[cactiuser@host ~]$  /usr/bin/php -q /usr/share/cacti/plugins/mURLin/scripts/query_sites.php 60 get downloadsize 2
131463

However, in the past we were able to run the command by hand and graph the following:
http://s16.postimg.org/fqnhbv8hh/Capture.png

Do you have any hints on this? Where else could I check for troubleshooting this?

PS: We're using mURLin because we think it's a good way to monitor HTTP related workloads, however if you have another (better) way of monitoring this kind of things, we appreciate.

Thanks in advance.

Best regards,

Bruno Martins

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