I have a slackware 8.0 installed.
On the module sysstats, the configuration module ommit
to add an information (variable) that i add in order
to make it work. Because, the server was complaining
thaht it couldn't find the cpu.rrd file. on the
file, /etc/webmin/sysstats/modules/cpu/cpu.sh if found
the last line was using rrdtool with the variable
${rddtables}, and i couldn't find the variable,
neither sysstats.cfg or cpu.cfg.
So I added into sysstats.cfg the variable.
rrdtables=/var/lib/rrdtools/
and it work perfectly fine now...
For your action
Fred