RRD broken after adding RRD summary package

[quazik]

pfSense 2.0.1

RRD graphs have been fine until today, when I tried installing the RRD summary package.  Now all the graphs come up as broken images, and rrdtool won't start.  I tried removing RRD summary, but that doesn't help.  I can't find anything more detailed in the logs than this:

Aug 27 11:54:13 gateway php: /status_rrd_graph_settings.php: Creating rrd update script
Aug 27 11:54:31 gateway apinger: Error while feeding rrdtool: Broken pipe
Aug 27 11:54:31 gateway apinger: /usr/local/bin/rrdtool respawning too fast, waiting 300s.

Any hints?