derivative(sumSeries(..)) vs sumSeries(derivative(..))

[omry]

Hi,
I have the a problem with a combined graph (cluster view) of a series I need to run through derivative.
The correct form should be:

sumSeries(derivative({web*}.network.netstat.active)

but instead pencil creates a graph using

derivative(sumSeries({web*}.network.netstat.active))

Since the counters on the web servers are not aligned, you get really messed up graphs from the second call.
This is my netstat graph definition, is there anything I can do to get a correct graph?

  netstat:
    title: Netstat
    targets:
      network.netstat.active:
        !omap
        - :color: orange
        - :derivative:
        - :key: Active
      network.netstat.established:
        !omap
        - :color: green
        - :derivative:
        - :key: Established
      network.netstat.failed:
        !omap
        - :color: red
        - :derivative:
        - :key: Failed
      network.netstat.passive:
        !omap
        - :color: blue
        - :derivative:
        - :key: Passive
      network.netstat.reset:
        !omap
        - :color: purple
        - :derivative:
        - :key: Reset
    hosts: [*]