JD can't start on xubuntu ?

Hi, sorry for my english, I'am french.
Today I try to test beta-0.5.547 version but it doesn't start. I Don't understand why?

The load screen don't appear and the program stops.

To know : I have java 1.6.0.0
Jdownloader 0.4.936 work good on the same system.

java -jar -Xmx512m JDownloader.jar
13 mai 2009 18:05:44 - INFO [jd.Main(main)] -> Start JDownloader
JAR
13 mai 2009 18:05:45 - LE PLUS FIN [jd.utils.JDUtilities(getJDClassLoader)] -> Create Classloader: for: /home/tomtom/JDownloader BETA 0.5547
13 mai 2009 18:05:45 - LE PLUS FIN [jd.JDClassLoader(<init>)] -> rootDir:/home/tomtom/JDownloader BETA 0.5547
/home/tomtom/JDownloader BETA 0.5547
file:/home/tomtom/JDownloader%20BETA%200.5547/jd
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDHJMerge.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDInfoFileWriter.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDLowSpeed.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDNewsfeeds.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDShutdown.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDUnrar.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDRemoteControl.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/schedule.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDWebinterface.jar
13 mai 2009 18:05:45 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDFolderWatch.jar
13 mai 2009 18:05:46 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDPremiumCollect.jar
13 mai 2009 18:05:46 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDHTTPLiveHeaderScripter.jar
13 mai 2009 18:05:46 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDTray.jar
13 mai 2009 18:05:46 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDLangFileEditor.jar
13 mai 2009 18:05:46 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/plugins/JDChat.jar
13 mai 2009 18:05:46 - PLUS FIN [jd.JDClassLoader(<init>)] -> Jar file loaded: /home/tomtom/JDownloader BETA 0.5547/JDownloader.jar
Exception in thread "main" java.lang.RuntimeException: Unexpected IOException while starting JUnique/Server for id "null"
at it.sauronsoftware.junique.Server.start(Server.java:115)
at it.sauronsoftware.junique.JUnique.acquireLock(JUnique.java:146)
at jd.Main.main(Unknown Source)
Caused by: java.net.BindException: Cannot assign requested address
at java.net.PlainSocketImpl.socketBind(Native Method)
at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:336)
at java.net.ServerSocket.bind(ServerSocket.java:336)
at java.net.ServerSocket.bind(ServerSocket.java:294)
at it.sauronsoftware.junique.Server.start(Server.java:104)
... 2 more
Exception in thread "Thread-1" java.lang.NullPointerException
at it.sauronsoftware.junique.Server.stop(Server.java:152)
at it.sauronsoftware.junique.JUnique.releaseLock(JUnique.java:205)
at it.sauronsoftware.junique.JUnique.access$3(JUnique.java:203)
at it.sauronsoftware.junique.JUnique$ShutdownHook.run(JUnique.java:424)
at java.lang.Thread.run(Thread.java:636)

And nothing ...
need help !!