Possible sporadic bug in GUI?

I am getting the below exception, sporadically, usually triggered by mouse clicks anywhere on the GUI. Doesn't seem to be related to any code I'm running in Matlab (i.e. no particular script or function). I am running Matlab 7.11.0 (2010b) on Ubuntu 12.04 LTS 64-bit, kernel 3.2.0-64. Is this a known bug and is there a fix? Or am I doing something wrong? Thanks.

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
  at com.mathworks.widgets.grouptable.GroupingTable.get(GroupingTable.java:1236)
  at com.mathworks.widgets.grouptable.GroupingTable$15.run(GroupingTable.java:469)
  at com.mathworks.widgets.grouptable.GroupingTable$15.run(GroupingTable.java:462)
  at com.mathworks.widgets.grouptable.GroupingTableModel.refresh(GroupingTableModel.java:550)
  at com.mathworks.widgets.grouptable.GroupingTableModel.ungroupOrRegroupRootLevelRows(GroupingTableModel.java:447)
  at com.mathworks.widgets.grouptable.GroupingTableModel.access$900(GroupingTableModel.java:27)
  at com.mathworks.widgets.grouptable.GroupingTableModel$6.commitRows(GroupingTableModel.java:411)
  at com.mathworks.widgets.grouptable.RowListTransactionTarget.finishTransaction(RowListTransactionTarget.java:115)
  at com.mathworks.widgets.grouptable.GroupingTableTransaction$1.run(GroupingTableTransaction.java:113)
  at java.awt.event.InvocationEvent.dispatch(Unknown Source)
  at java.awt.EventQueue.dispatchEvent(Unknown Source)
  at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
  at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
  at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
  at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
  at java.awt.EventDispatchThread.run(Unknown Source)