Joining and unjoining graphs screws up Preferences>tracks

Scenario 1. load two graphs and open the preferences > tracks. Now join those 2 graphs. They disappear from the table. Now unjoin. The two graphs repopulate the table, but you lose the other tracks. Close prefs, reopen, everything is back to normal.

Scenario 2. Load 2 graphs, open prefs, join. NOW close prefs... THEN unjoin. Try to reopen prefs, get this error:

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at com.affymetrix.igb.trackAdjuster.TrackPreferencesSeqMapViewPanel.collectSymsAndGlyphs(TrackPreferencesSeqMapViewPanel.java:55)
at com.affymetrix.igb.trackAdjuster.TrackPreferencesSeqMapViewPanel.refreshSelection(TrackPreferencesSeqMapViewPanel.java:118)
at com.affymetrix.igb.trackAdjuster.TrackPreferencesSeqMapViewPanel.trackstylePropertyChanged(TrackPreferencesSeqMapViewPanel.java:170)
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.prefs.TierPrefsView.refreshList(TierPrefsView.java:237)
at com.affymetrix.igb.prefs.TierPreferencesPanel.mapRefresh(TierPreferencesPanel.java:37)
at com.affymetrix.igb.view.SeqMapView.setAnnotatedSeq(SeqMapView.java:893)
at com.affymetrix.igb.view.SeqMapView.setAnnotatedSeq(SeqMapView.java:724)
at com.affymetrix.igb.trackOperations.TrackOperationsTab$5.run(TrackOperationsTab.java:204)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:682)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:643)
at java.awt.EventQueue$1.run(EventQueue.java:641)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:652)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:296)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:211)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:196)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:188)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)
Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at com.affymetrix.igb.trackAdjuster.TrackPreferencesSeqMapViewPanel.collectSymsAndGlyphs(TrackPreferencesSeqMapViewPanel.java:55)
at com.affymetrix.igb.trackAdjuster.TrackPreferencesSeqMapViewPanel.refreshSelection(TrackPreferencesSeqMapViewPanel.java:118)
at com.affymetrix.igb.trackAdjuster.TrackPreferencesSeqMapViewPanel.trackstylePropertyChanged(TrackPreferencesSeqMapViewPanel.java:170)
at com.affymetrix.igb.shared.TrackstylePropertyMonitor.firePropertyChanged(TrackstylePropertyMonitor.java:47)
at com.affymetrix.igb.shared.TrackstylePropertyMonitor.tableChanged(TrackstylePropertyMonitor.java:29)
at javax.swing.table.AbstractTableModel.fireTableChanged(AbstractTableModel.java:280)
at javax.swing.table.AbstractTableModel.fireTableDataChanged(AbstractTableModel.java:182)
at com.affymetrix.igb.prefs.TierPrefsView.refreshList(TierPrefsView.java:237)
at com.affymetrix.igb.prefs.TierPreferencesPanel.refresh(TierPreferencesPanel.java:31)
at com.affymetrix.igb.prefs.PreferencesPanel.setTab(PreferencesPanel.java:97)
at com.affymetrix.igb.action.PreferencesAction.actionPerformed(PreferencesAction.java:50)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2028)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2351)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:387)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:242)
at javax.swing.AbstractButton.doClick(AbstractButton.java:389)
at com.apple.laf.ScreenMenuItem.actionPerformed(ScreenMenuItem.java:95)
at java.awt.MenuItem.processActionEvent(MenuItem.java:627)
at java.awt.MenuItem.processEvent(MenuItem.java:586)
at java.awt.MenuComponent.dispatchEventImpl(MenuComponent.java:337)
at java.awt.MenuComponent.dispatchEvent(MenuComponent.java:325)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:687)
at java.awt.EventQueue.access$000(EventQueue.java:85)
at java.awt.EventQueue$1.run(EventQueue.java:643)
at java.awt.EventQueue$1.run(EventQueue.java:641)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:98)
at java.awt.EventQueue$2.run(EventQueue.java:657)
at java.awt.EventQueue$2.run(EventQueue.java:655)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:654)
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)