Error when opening preferences

[Cobra]

What steps will reproduce the problem?

1. Open preferences dialog

What is the expected result?
preferences dialog is displayed

What happens instead?
This error; preferences dialog is displayed afterwards.

Please provide any additional information below. Attach a screenshot if
possible.

Build-Date: 2011-08-28 14:52:24
Revision: 4376
Is-Local-Build: true

Identification: JOSM/1.5 (4376 SVN en)
Memory Usage: 264 MB / 910 MB (125 MB allocated, but free)
Java version: 1.6.0_26, Sun Microsystems Inc., Java HotSpot(TM) 64-Bit Server VM
Operating system: Linux
Dataset consistency test: No problems found

Plugin: ImportImagePlugin (26530)
Plugin: ImproveWayAccuracy (26530)
Plugin: PicLayer (26530)
Plugin: alignways (26530)
Plugin: licensechange (26570)
Plugin: measurement (26375)
Plugin: openstreetbugs (26530)
Plugin: openvisible (26530)
Plugin: proj4j (26509)
Plugin: reverter (26530)
Plugin: terracer (26406)
Plugin: undelete (26530)
Plugin: utilsplugin2 (26530)

java.lang.NoSuchMethodError: org.openstreetmap.josm.data.preferences.IntegerProperty.getDefaultValue()I
	at org.openstreetmap.josm.gui.preferences.BackupPreference.addGui(BackupPreference.java:52)
	at org.openstreetmap.josm.gui.preferences.PreferenceTabbedPane.buildGui(PreferenceTabbedPane.java:232)
	at org.openstreetmap.josm.gui.preferences.PreferenceDialog.build(PreferenceDialog.java:51)
	at org.openstreetmap.josm.gui.preferences.PreferenceDialog.<init>(PreferenceDialog.java:64)
	at org.openstreetmap.josm.actions.PreferencesAction.run(PreferencesAction.java:38)
	at org.openstreetmap.josm.actions.PreferencesAction.actionPerformed(PreferencesAction.java:34)
	at javax.swing.SwingUtilities.notifyAction(SwingUtilities.java:1639)
	at javax.swing.JComponent.processKeyBinding(JComponent.java:2851)
	at javax.swing.KeyboardManager.fireBinding(KeyboardManager.java:267)
	at javax.swing.KeyboardManager.fireKeyboardAction(KeyboardManager.java:229)
	at javax.swing.JComponent.processKeyBindingsForAllComponents(JComponent.java:2928)
	at javax.swing.JComponent.processKeyBindings(JComponent.java:2920)
	at javax.swing.JComponent.processKeyEvent(JComponent.java:2814)
	at java.awt.Component.processEvent(Component.java:6065)
	at java.awt.Container.processEvent(Container.java:2041)
	at java.awt.Component.dispatchEventImpl(Component.java:4651)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.KeyboardFocusManager.redispatchEvent(KeyboardFocusManager.java:1850)
	at java.awt.DefaultKeyboardFocusManager.dispatchKeyEvent(DefaultKeyboardFocusManager.java:712)
	at java.awt.DefaultKeyboardFocusManager.preDispatchKeyEvent(DefaultKeyboardFocusManager.java:990)
	at java.awt.DefaultKeyboardFocusManager.typeAheadAssertions(DefaultKeyboardFocusManager.java:855)
	at java.awt.DefaultKeyboardFocusManager.dispatchEvent(DefaultKeyboardFocusManager.java:676)
	at java.awt.Component.dispatchEventImpl(Component.java:4523)
	at java.awt.Container.dispatchEventImpl(Container.java:2099)
	at java.awt.Window.dispatchEventImpl(Window.java:2478)
	at java.awt.Component.dispatchEvent(Component.java:4481)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:643)
	at java.awt.EventQueue.access$000(EventQueue.java:84)
	at java.awt.EventQueue$1.run(EventQueue.java:602)
	at java.awt.EventQueue$1.run(EventQueue.java:600)
	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:616)
	at java.awt.EventQueue$2.run(EventQueue.java:614)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:87)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:613)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:269)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:184)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:174)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:169)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:161)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:122)

[Cobra]

did a clean checkout and it disappeared. seems to be a local problem.