This when made standars validation check...

[mcheck]

Revision: 5875
Build-Date: 2013-04-17 01:34:35
Last Changed Date: 2013-04-17 00:28:38 +0200 (Wed, 17 Apr 2013)
Last Changed Rev: 5875
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Author: Don-vip
Repository Root: http://josm.openstreetmap.de/svn
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b

Identification: JOSM/1.5 (5875 it) Linux Ubuntu 12.04.2 LTS
Memory Usage: 329 MB / 723 MB (102 MB allocated, but free)
Java version: 1.8.0-ea, Oracle Corporation, Java HotSpot(TM) 64-Bit Server VM
Dataset consistency test: No problems found

Plugin: AddrInterpolation (29435)
Plugin: FastDraw (29457)
Plugin: FixAddresses (29500)
Plugin: HouseNumberTaggingTool (29487)
Plugin: ImportImagePlugin (29435)
Plugin: OpeningHoursEditor (29435)
Plugin: PicLayer (29505)
Plugin: RoadSigns (29435)
Plugin: SimplifyArea (29435)
Plugin: buildings_tools (29435)
Plugin: continuosDownload (28565)
Plugin: contourmerge (1003)
Plugin: dataimport (29435)
Plugin: download_along (29435)
Plugin: ext_tools (29435)
Plugin: geotools (29435)
Plugin: graphview (29435)
Plugin: imageryadjust (29435)
Plugin: importvec (29435)
Plugin: irsrectify (29210)
Plugin: jts (29435)
Plugin: lakewalker (29435)
Plugin: log4j (29435)
Plugin: mirrored_download (29505)
Plugin: multipoly-convert (29435)
Plugin: namemanager (29435)
Plugin: opendata (29505)
Plugin: openstreetbugs (29435)
Plugin: pbf (29435)
Plugin: pdfimport (29435)
Plugin: photo_geotagging (29435)
Plugin: plastic_laf (29435)
Plugin: print (29435)
Plugin: proj4j (29435)
Plugin: reltoolbox (29459)
Plugin: reverter (29503)
Plugin: scripting (30300)
Plugin: tag2link (29461)
Plugin: tageditor (29435)
Plugin: tagging-preset-tester (29435)
Plugin: terracer (29435)
Plugin: utilsplugin2 (29435)
Plugin: walkingpapers (29480)
Plugin: waypoint_search (29435)
Plugin: wikipedia (29435)
Plugin: wms-turbo-challenge2 (29435)

sun.awt.X11.XException: Cannot write XdndAware property
	at sun.awt.X11.XDnDDropTargetProtocol.registerDropTarget(XDnDDropTargetProtocol.java:97)
	at sun.awt.X11.XDropTargetRegistry.registerDropSite(XDropTargetRegistry.java:571)
	at sun.awt.X11.XWindowPeer.addDropTarget(XWindowPeer.java:1929)
	at sun.awt.X11.XComponentPeer.addDropTarget(XComponentPeer.java:1330)
	at java.awt.dnd.DropTarget.addNotify(DropTarget.java:509)
	at java.awt.Component.addNotify(Component.java:6921)
	at java.awt.Container.addNotify(Container.java:2758)
	at javax.swing.JComponent.addNotify(JComponent.java:4741)
	at java.awt.Container.addNotify(Container.java:2769)
	at javax.swing.JComponent.addNotify(JComponent.java:4741)
	at java.awt.Container.addNotify(Container.java:2769)
	at javax.swing.JComponent.addNotify(JComponent.java:4741)
	at java.awt.Container.addNotify(Container.java:2769)
	at javax.swing.JComponent.addNotify(JComponent.java:4741)
	at java.awt.Container.addNotify(Container.java:2769)
	at javax.swing.JComponent.addNotify(JComponent.java:4741)
	at java.awt.Container.addNotify(Container.java:2769)
	at javax.swing.JComponent.addNotify(JComponent.java:4741)
	at javax.swing.JRootPane.addNotify(JRootPane.java:757)
	at java.awt.Container.addNotify(Container.java:2769)
	at java.awt.Window.addNotify(Window.java:770)
	at java.awt.Dialog.addNotify(Dialog.java:760)
	at java.awt.Window.pack(Window.java:807)
	at org.openstreetmap.josm.gui.PleaseWaitDialog.adjustLayout(PleaseWaitDialog.java:93)
	at org.openstreetmap.josm.gui.PleaseWaitDialog.setCustomText(PleaseWaitDialog.java:104)
	at org.openstreetmap.josm.gui.PleaseWaitDialog.initDialog(PleaseWaitDialog.java:66)
	at org.openstreetmap.josm.gui.PleaseWaitDialog.<init>(PleaseWaitDialog.java:83)
	at org.openstreetmap.josm.gui.progress.PleaseWaitProgressMonitor$4.run(PleaseWaitProgressMonitor.java:155)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:251)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:726)
	at java.awt.EventQueue.access$200(EventQueue.java:103)
	at java.awt.EventQueue$3.run(EventQueue.java:687)
	at java.awt.EventQueue$3.run(EventQueue.java:685)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$1.doIntersectionPrivilege(ProtectionDomain.java:75)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:696)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:216)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:135)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:123)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:119)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:111)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:97)

[Don-vip]

Closed as duplicate of #8613.
Please give us some info in #8613 instead of posting duplicates of the same bug :) Can you try with Java 7 ?

By the way you're facing a lot of bugs with all your installed plugins, you really should uninstall those you are not using on a daily basis.