I have also found the following in the rrd.journal file located in /opt/zenoss/var/rrd_journals
Devices that are graphing correctly are getting updates then writing the file:
update /opt/zenoss/perf/Devices/10.7.108.241/HNSN-DNVR-TwoWayD_HNSN-DNVR-TwoWayD.rrd 1374638107:605
wrote /opt/zenoss/perf/Devices/10.7.108.241/HNSN-DNVR-TwoWayD_HNSN-DNVR-TwoWayD.rrd
update /opt/zenoss/perf/Devices/10.7.108.241/HNSN-PLY-TwoWayD_HNSN-PLY-TwoWayD.rrd 1374638107:38734
wrote /opt/zenoss/perf/Devices/10.7.108.241/HNSN-PLY-TwoWayD_HNSN-PLY-TwoWayD.rrd
update /opt/zenoss/perf/Devices/10.7.108.241/HNSN-PTL-TwoWayD_HNSN-PTL-TwoWayD.rrd 1374638107:34305
wrote /opt/zenoss/perf/Devices/10.7.108.241/HNSN-PTL-TwoWayD_HNSN-PTL-TwoWayD.rrd
update /opt/zenoss/perf/Devices/10.7.108.241/HNSN-SLC-TwoWayD_HNSN-SLC-TwoWayD.rrd 1374638107:11887
wrote /opt/zenoss/perf/Devices/10.7.108.241/HNSN-SLC-TwoWayD_HNSN-SLC-TwoWayD.rrd
On the device that is not graphing correctly it is writing the file, then getting the updates. The updates show that it is actually getting the correct data, but the files are being written before getting the updates:
wrote /opt/zenoss/perf/Devices/10.7.100.241/DNVR-PLY-TwoWayD_DNVR-PLY-TwoWayD.rrd
wrote /opt/zenoss/perf/Devices/10.7.100.241/DNVR-HNSN-TwoWayD_DNVR-HNSN-TwoWayD.rrd
wrote /opt/zenoss/perf/Devices/10.7.100.241/DNVR-SLC-TwoWayD_DNVR-SLC-TwoWayD.rrd
wrote /opt/zenoss/perf/Devices/10.7.100.241/DNVR-PTL-TwoWayD_DNVR-PTL-TwoWayD.rrd
update /opt/zenoss/perf/Devices/10.7.100.241/DNVR-PLY-TwoWayD_DNVR-PLY-TwoWayD.rrd 1374638063:31466
update /opt/zenoss/perf/Devices/10.7.100.241/DNVR-HNSN-TwoWayD_DNVR-HNSN-TwoWayD.rrd 1374638063:610
update /opt/zenoss/perf/Devices/10.7.100.241/DNVR-PTL-TwoWayD_DNVR-PTL-TwoWayD.rrd 1374638063:53534
update /opt/zenoss/perf/Devices/10.7.100.241/DNVR-SLC-TwoWayD_DNVR-SLC-TwoWayD.rrd 1374638063:12467
Still working on figuring this out...