NeighborhoodReporter not scheduled

There seems to be an issue with NeighborhoodReporter (or maybe even all Reporters) that causes them to not be scheduled properly and therefore not executed.

In the attached model (directed_transport.xml), I try to model directed transport of some cargo (Property) using 'transporter' proteins (MembraneProperty) that are unequally distributed over the membrane. Do to this, I need to report the amount of cargo around a cell in a MembraneProperty called 'cargo_mem' using a NeighborhoodReporter.

However, despite the fact that the output symbol 'cargo_mem' is used (by System and by Gnuplotter), the Reporter is not scheduled and never executed.

All seems well during initialization. The System and Gnuplotter plugins propagate their time steps to the NeighborhoodReporter:

 TimeStepListener "System" propagates its time step 1
 Upstream: 
 -> cargo_mem
 Propagate up to NeighborhoodReporter
 -> transporters
 Downstream: 
-> flux
 Propagate down to Gnuplotter

 TimeStepListener "Gnuplotter" propagates its time step 1
 Upstream: 
 -> cargo
 -> cargo_mem
 Propagate up to NeighborhoodReporter
 -> flux
 Propagate up to System
 -> transporters

However, later on, the schedule shows that their time steps are NOT propagated to the NeighborhoodReporter (its time step is still "-1"):

======================================================
 Time Schedule
======================================================
 Time precision patch is 0

=====|    Phase I     |===============================
-----. Reactions .------------------------------------
  + 1 => System [cargo_mem,transporters] -> [flux]

=====|    Phase II    |===============================
-----. Reporters and Instantaneous Processes.---------
  + -1 => NeighborhoodReporter [cargo,cell.center] -> [cargo_mem]

=====|    Phase III   |===============================
-----. Analysis .-------------------------------------
  + 1 => Gnuplotter [cargo,cargo_mem,flux,transporters] 
------------------------------------------------------
======================================================

== Model == directed_transport.xml