[yaala] lib/Data/Core.pm: Unavailable aggregation requested: ``requests''. Returning 0

[newman]

Dear Developers,

    Congratulations, I loved the concept you used in this software, 
never see something so versatile, so flexible.

    I am trying yaala-0.6.7, but I am some basic error here:
    myconfig is:

[root@newman yaala-0.6.7]# cat config.squid
directory: 'squid';
logtype: 'Squid';
select: "requests BY date, client";
html_stylesheet: 'style.css';
print-graphs: 'true';
graph_height: 250;
graph_width: 500;

The command I try is:
[root@newman yaala-0.6.7]# ./yaala --config config.squid   
/var/log/squid/access.log

but i receive this error:
lib/Data/Core.pm: Unavailable aggregation requested: ``requests''. 
Returning 0.
   

    I tryied all samples you send with the software, but always give 
Unavailable aggregation requested.

    I apreciate any help,

    Thanks,

    Newman