[hobbit] weird rrd output (using the NCV module)

["Gary Baluha" <gumby3203 (at) gmail.com>]

I'm seeing a weird output for one of my custom RRD graphs, using the NCV
module.  The collector script on the client
is creating an ncv-style output based on the bind 9 "rndc stats" command.
These numbers are counter-style numbers,
always increasing (until named is restarted).  As such, the default DERIVE
format of the NCV module is correct.

The problem I'm seeing is that the numbers showing up in the RRD graph--as
far as I can tell--have nothing at all to do
with the actual "rndc stats" values.  For instance, the "last" and "current"
values of the data was:

success : 283  ->  294  (11)
referral : 0  ->  0  (0)
nxrrset : 149  ->  156  (7)
nxdomain : 298  ->  312  (14)
recursion : 247  ->  254  (7)
failure : 400  ->  400  (0)
duplicate : 0  ->  0  (0)
dropped : 0  ->  0  (0)

The number in () above is the actual difference between the numbers, and the
values I'm expecting to show up in the RRD graph.
But the actual values that are showing up for the above example (for the
"(cur)" value) are, respectively:
34.0m
0.0
20.8m
41.6m
25.6m
0.0
0.0
0.0

These numbers don't correspond to any value, anywhere.  Any idea where these
numbers are coming from?  I can post the
relevant section of the hobbitgraph.cfg file if that would help.  I'm not
sure if this is an RRD issue or Hobbit issue, but when
I use rrdtool to dump the actual RRD file, the value for "<last_ds>" is the
correct value.