Trend Graphs Stopped Showing Data

["Mike Livenspargar" <mlivensp (at) sonoma-county.org>]

We are a new installation of Hobbit 4.2.0, running on SuSE
Linux ES 10 SP1 machines. All has been working fine for a
couple of months until yesterday when the CPU load and Users
and Processes trend graphs for a particular machine stopped
showing data. All other trend graphs for that machine appear
to be working correctly. The graphs appear on the Trends
page, but the last 16 hours or so show no data for those two
graphs.
 
I'm not familiar with rrd but I do see that the procs.rrd,
users.rrd and la.rrd files on the hobbit server have
datetime stamps coinciding with the last reported data
(about 16 hours ago). The other .rrd files have current
datetime stamps. I've tried restarting the hobbit server and
the client but that did not fix the problem.
 
What steps can I take to try to resolve this problem?
 
Thank you,
Mike