It seems with more than 5 or 6 datasets loaded (I am using RES3 buildings and several result datasets built from it), I get concurrent modification exceptions in the RendererContext. It's seems fairly reproducible.

[RendererContext]: Failed
java.util.ConcurrentModificationException
at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:761)
at java.util.LinkedList$ListItr.next(LinkedList.java:696)
at ncsa.gis.listeners.MemberChangedListenerSupport.fireChanged(MemberChangedListenerSupport.java:26)
at ncsa.gis.types.RendererContext.fireChanged(RendererContext.java:129)
at ncsa.gis.types.RendererContext.access$1(RendererContext.java:127)
at ncsa.gis.types.RendererContext$1$1.changed(RendererContext.java:154)
at ncsa.gis.listeners.MemberChangedListenerSupport.fireChanged(MemberChangedListenerSupport.java:27)
at ncsa.gis.types.GISMapLayer.setRoiFilter(GISMapLayer.java:210)
at ncsa.gis.types.RendererContext$1.run(RendererContext.java:199)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:55)