Bonjour

Lors de l'installation d'un composant dans Eclipse, à partir du gestionnaire de mises à jour, j'obtiens l'erreur suivante :
An error occurred while collecting items to be installed
No repository found containing: com.caucho.hessian/osgi.bundle/3.1.3
No repository found containing: javax.activation/osgi.bundle/1.1.0.v200906290531
No repository found containing: javax.mail/osgi.bundle/1.4.0.v200905040518
No repository found containing: javax.persistence/osgi.bundle/1.99.0.v200906021518
No repository found containing: javax.transaction/osgi.bundle/1.1.1.v200909161740
No repository found containing: javax.xml.soap/osgi.bundle/1.3.0.v200904281458
No repository found containing: org.apache.oro/osgi.bundle/2.0.8.v200903061218
No repository found containing: org.apache.velocity/osgi.bundle/1.5.0.v200905192330
No repository found containing: org.eclipse.core.databinding/osgi.bundle/1.2.0.M20090819-0800
No repository found containing: org.eclipse.core.databinding.observable/osgi.bundle/1.2.0.M20090902-0800
No repository found containing: org.eclipse.core.databinding.property/osgi.bundle/1.2.0.M20090819-0800
No repository found containing: org.eclipse.dltk.core/osgi.bundle/1.0.1.v20090910-1601
No repository found containing: org.eclipse.dltk.debug/osgi.bundle/1.0.0.v20090613-1432
No repository found containing: org.eclipse.dltk.formatter/osgi.bundle/1.0.1.v20090903-2153
No repository found containing: org.eclipse.dltk.launching/osgi.bundle/1.0.1.v20090910-1601
No repository found containing: org.eclipse.dltk.ruby.core/osgi.bundle/1.0.0.v20090613-1432
No repository found containing: org.eclipse.dltk.ruby.formatter/osgi.bundle/1.0.0.v20090617-1157
No repository found containing: org.eclipse.dltk.ruby.ui/osgi.bundle/1.0.0.v20090613-1432
No repository found containing: org.eclipse.dltk.ui/osgi.bundle/1.0.1.v20090903-2153
No repository found containing: org.eclipse.net4j.spring/osgi.bundle/0.7.1.v200610271244
No repository found containing: org.eclipse.net4j.util/osgi.bundle/2.0.0.v200906160348
No repository found containing: org.eclipse.persistence.antlr/osgi.bundle/1.1.2.v20090612-r4475
No repository found containing: org.eclipse.persistence.asm/osgi.bundle/1.1.2.v20090612-r4475
No repository found containing: org.eclipse.persistence.core/osgi.bundle/1.1.2.v20090612-r4475
No repository found containing: org.eclipse.persistence.jpa/osgi.bundle/1.1.2.v20090612-r4475
No repository found containing: org.eclipse.rap.jface/osgi.bundle/1.2.1.20090813-1453
No repository found containing: org.eclipse.rap.jface.databinding/osgi.bundle/1.2.1.20090813-1453
No repository found containing: org.eclipse.rap.rwt/osgi.bundle/1.2.1.20090813-1453
No repository found containing: org.eclipse.rap.ui/osgi.bundle/1.2.1.20090813-1453
No repository found containing: org.eclipse.rap.ui.workbench/osgi.bundle/1.2.1.20090813-1453
No repository found containing: org.eclipse.tptp.platform.agentcontroller/osgi.bundle/4.2.301.v200909111546
No repository found containing: org.eclipse.tptp.platform.iac.administrator/osgi.bundle/4.4.301.v200908220100
No repository found containing: org.mortbay.management/osgi.bundle/6.1.15.v200909161740
Quelqu'un saurait-il m'expliquer d'où vient le problème ?

Merci d'avance pour votre aide.