Load a few tracks. clear data from track. Then reload (without moving or zooming out)

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at java.util.concurrent.CopyOnWriteArrayList.<init>(CopyOnWriteArrayList.java:91)
at com.affymetrix.genometryImpl.symmetry.SimpleSeqSymmetry.equals(SimpleSeqSymmetry.java:123)
at com.affymetrix.genometryImpl.symmetry.SimpleSymWithProps.equals(SimpleSymWithProps.java:122)
at com.affymetrix.genometryImpl.symmetry.GraphSym.equals(GraphSym.java:615)
at java.util.HashMap.get(HashMap.java:305)
at com.affymetrix.igb.shared.GraphGlyphUtils.getPercents2Scores(GraphGlyphUtils.java:136)
at com.affymetrix.igb.shared.GraphGlyphUtils.getPercentForValue(GraphGlyphUtils.java:166)
at com.affymetrix.igb.trackAdjuster.GraphVisibleBoundsSetter.initPercents(GraphVisibleBoundsSetter.java:309)
at com.affymetrix.igb.trackAdjuster.GraphVisibleBoundsSetter.setGraphs(GraphVisibleBoundsSetter.java:189)
at com.affymetrix.igb.trackAdjuster.TrackAdjusterTab.resetGraphAndRangePanel(TrackAdjusterTab.java:499)
at com.affymetrix.igb.trackAdjuster.TrackAdjusterTab.refreshSelection(TrackAdjusterTab.java:310)
at com.affymetrix.igb.trackAdjuster.TrackAdjusterTab.trackstylePropertyChanged(TrackAdjusterTab.java:808)
at com.affymetrix.igb.shared.TrackstylePropertyMonitor.firePropertyChanged(TrackstylePropertyMonitor.java:47)
at com.affymetrix.igb.shared.TrackstylePropertyMonitor.tableChanged(TrackstylePropertyMonitor.java:29)
at javax.swing.table.AbstractTableModel.fireTableChanged(AbstractTableModel.java:280)
at javax.swing.table.AbstractTableModel.fireTableDataChanged(AbstractTableModel.java:182)
at com.affymetrix.igb.view.load.DataManagementTableModel.createVirtualFeatures(DataManagementTableModel.java:91)
at com.affymetrix.igb.view.load.GeneralLoadView$5.run(GeneralLoadView.java:448)
at com.affymetrix.genometryImpl.util.ThreadUtils.runOnEventQueue(ThreadUtils.java:29)
at com.affymetrix.igb.view.load.GeneralLoadView.refreshDataManagementTable(GeneralLoadView.java:444)
at com.affymetrix.igb.view.load.GeneralLoadView.refreshDataManagementView(GeneralLoadView.java:456)
at com.affymetrix.igb.view.load.GeneralLoadUtils$3.finished(GeneralLoadUtils.java:781)
at com.affymetrix.genometryImpl.thread.CThreadWorker.done(CThreadWorker.java:41)
at javax.swing.SwingWorker$5.run(SwingWorker.java:717)
at javax.swing.SwingWorker$DoSubmitAccumulativeRunnable.run(SwingWorker.java:814)
at sun.swing.AccumulativeRunnable.run(AccumulativeRunnable.java:95)
at javax.swing.SwingWorker$DoSubmitAccumulativeRunnable.actionPerformed(SwingWorker.java:824)
at javax.swing.Timer.fireActionPerformed(Timer.java:291)
at javax.swing.Timer$DoPostEvent.run(Timer.java:221)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:677)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:638)
at java.awt.EventQueue$1.run(EventQueue.java:636)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:647)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)