Dragging tabs into it's own group, sporadic java.lang.NullPointerException

Hi I was dragging tabs from the main window to into a separate window (to form a new sql tab group).... while dragging tab#5 into the window, i get the error below: However... when i skip a tab and drag it over, ---- no issues... when i try that tab again, the error comes up again.... fyi.. debug window is not showing any activity.. An internal error occurred in: java.lang.NullPointerException The error may have affected the application state. Please to vendor. Details: Type: java.lang.NullPointerException Stack Trace: java.lang.NullPointerException at com.jidesoft.docking.b.f(Unknown Source) at com.jidesoft.docking.DefaultDockingManager.findFloatingComponentAt(Unknown Source) at com.jidesoft.docking.j.dragFrame(Unknown Source) at com.jidesoft.docking.DefaultDockingManager.dragFrame(Unknown Source) at com.jidesoft.docking.i.mouseDragged(Unknown Source) at java.awt.AWTEventMulticaster.mouseDragged(Unknown Source) at java.awt.AWTEventMulticaster.mouseDragged(Unknown Source) at java.awt.Component.processMouseMotionEvent(Unknown Source) at javax.swing.JComponent.processMouseMotionEvent(Unknown Source) at java.awt.Component.processEvent(Unknown Source) at java.awt.Container.processEvent(Unknown Source) at java.awt.Component.dispatchEventImpl(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source) at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source) at java.awt.Container.dispatchEventImpl(Unknown Source) at java.awt.Window.dispatchEventImpl(Unknown Source) at java.awt.Component.dispatchEvent(Unknown Source) at java.awt.EventQueue.dispatchEventImpl(Unknown Source) at java.awt.EventQueue.access$400(Unknown Source) at java.awt.EventQueue$2.run(Unknown Source) at java.awt.EventQueue$2.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source) at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.awt.EventQueue$3.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.security.AccessControlContext$1.doIntersectionPrivilege(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at com.onseven.dbvis.N.A._.dispatchEvent(Z:483) 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) System Information: Product: DbVisualizer Pro 9.1.6 Build: #2117 (2014/01/26 21:20) Java VM: Java HotSpot(TM) Client VM Java Version: 1.6.0_65 Java Vendor: Sun Microsystems Inc. OS Name: Windows 7 OS Arch: x86 OS Version: 6.1