error while request small map area

[anonymous]

what happend:
trash the existing data layer in josm and hold gpx file loaded;
push dowoload buttom for downloading new small area (100m);
error message in a separat window is shown;
the requested area is shown a second later in the main window, too.

Repository Root: http://josm.openstreetmap.de/svn
Build-Date: 2010-05-25 12:22:44
Last Changed Author: stoecker
Revision: 3279
Repository UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
URL: http://josm.openstreetmap.de/svn/trunk
Last Changed Date: 2010-05-24 23:36:44 +0200 (Mon, 24 May 2010)
Last Changed Rev: 3279

Memory Usage: 81 MB / 643 MB (20 MB allocated, but free)
Java version: 1.6.0_18, Sun Microsystems Inc., OpenJDK 64-Bit Server VM
Operating system: Linux (Kubuntu 10.04)

Plugins: DirectUpload,editgpx,measurement,openstreetbugs,turnrestrictions,validator
Plugin openstreetbugs (Version: 20696)
Plugin editgpx (Version: 19683)
Plugin DirectUpload (Version: 20881)
Plugin validator (Version: 21177)
Plugin turnrestrictions (Version: 21186)
Plugin measurement (Version: 19681)

java.lang.NoSuchFieldError: <init>

at com.sun.imageio.plugins.png.PNGMetadata.<init>(PNGMetadata.java)
at com.sun.imageio.plugins.png.PNGImageReader.<init>(PNGImageReader.java:186)
at com.sun.imageio.plugins.png.PNGImageReaderSpi.createReaderInstance(PNGImageReaderSpi.java:103)
at javax.imageio.spi.ImageReaderSpi.createReaderInstance(ImageReaderSpi.java:317)
at javax.imageio.ImageIO$ImageReaderIterator.next(ImageIO.java:519)
at javax.imageio.ImageIO$ImageReaderIterator.next(ImageIO.java:503)
at javax.imageio.ImageIO.read(ImageIO.java:1433)
at javax.imageio.ImageIO.read(ImageIO.java:1342)
at org.openstreetmap.gui.jmapviewer.Tile.loadImage(Tile.java:165)
at org.openstreetmap.gui.jmapviewer.OsmFileCacheTileLoader$FileLoadJob.loadOrUpdateTile(OsmFileCacheTileLoader.java:201)
at org.openstreetmap.gui.jmapviewer.OsmFileCacheTileLoader$FileLoadJob.run(OsmFileCacheTileLoader.java:144)
at org.openstreetmap.gui.jmapviewer.JobDispatcher$JobThread.executeJobs(JobDispatcher.java:124)
at org.openstreetmap.gui.jmapviewer.JobDispatcher$JobThread.run(JobDispatcher.java:98)