mrtg suddenly broken

[Net Llama!]

I've got mrtg setup on one system at home just to monitor the amount of 
traffic going over eth0 (the only NIC/interface on the system).  I set 
this up over a year ago, and its been working fine ever since.  Until 
today, when I happened to take a look at the graphs and noticed that 
they've basically flatlined.

For example, I've had 25KB/s or more coming down eth0 for the past hour, 
yet the graph for the past 24hours is a huge flat line at 0KB/s except for 
a strange spike up to 4.8KB/s yesterday afternoon.

The cronjob (which runs every 5 minutes) is:
*/5 * * * * root LANG=C LC_ALL=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg --lock-file /var/lock/mrtg/mrtg_l --confcache-file /var/lib/mrtg/mrtg.ok

Running it manually returns no errors, but the graphs are still not 
accurate.

/etc/mrtg/mrtf.cfg looks like this:
##############################
WorkDir: /var/www/mrtg
ThreshDir: /var/www/mrtg

Target[r1]: 1:public at hal:
SetEnv[r1]: MRTG_INT_IP="10.0.0.1" MRTG_INT_DESCR="eth0"
MaxBytes[r1]: 1250000
Title[r1]: Traffic Analysis for eth0
PageTop[r1]: <H1>Stats for eth0</H1>
##############################

eth0 is 10.0.0.1 on my box.

I've changed nothing in the mrtg configuration, so I'm completely stumped 
on why its failing to record much of anything.  Anyone have any 
suggestions how or where to start troubleshooting this?

thanks.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Lonni J Friedman                        netllama at linux-sxs.org
LlamaLand				http://netllama.linux-sxs.org