Can full backups include the plugins folder? it only back users and jobs folder

ls -ltr /var/jenkins/backup/FULL-2011-09-09_05-00/
rw-rr- 1 jenkins jenkins 215 Aug 24 16:10 hudson.triggers.SCMTrigger.xml
rw-rr- 1 jenkins jenkins 76 Aug 24 16:10 hudson.tasks.Shell.xml
rw-rr- 1 jenkins jenkins 132 Aug 24 16:10 hudson.tasks.Maven.xml
rw-rr- 1 jenkins jenkins 514 Aug 24 16:10 hudson.tasks.Mailer.xml
rw-rr- 1 jenkins jenkins 128 Aug 24 16:10 hudson.tasks.Ant.xml
rw-rr- 1 jenkins jenkins 666 Aug 24 16:10 hudson.scm.SubversionSCM.xml
rw-rr- 1 jenkins jenkins 179 Aug 24 16:10 hudson.scm.CVSSCM.xml
rw-rr- 1 jenkins jenkins 353 Aug 24 16:10 hudson.plugins.skype.im.transport.SkypePublisher.xml
rw-rr- 1 jenkins jenkins 188 Aug 24 16:10 hudson.plugins.mercurial.MercurialInstallation.xml
rw-rr- 1 jenkins jenkins 713 Aug 24 16:10 hudson.plugins.ircbot.IrcPublisher.xml
rw-rr- 1 jenkins jenkins 698 Aug 24 16:10 hudson.maven.MavenModuleSet.xml
rw-rr- 1 jenkins jenkins 694 Sep 5 18:22 backup.xml
rw-rr- 1 jenkins jenkins 526 Sep 6 11:57 thinBackup.xml
rw-rr- 1 jenkins jenkins 5399 Sep 6 18:08 config.xml
rw-rr- 1 jenkins jenkins 159 Sep 7 10:50 hudson.model.UpdateCenter.xml
rw-rr- 1 jenkins jenkins 907 Sep 7 10:50 nodeMonitors.xml
drwxr-xr-x 19 jenkins jenkins 4096 Sep 9 05:00 jobs
drwxr-xr-x 4 jenkins jenkins 34 Sep 9 05:00 users
rw-rr- 1 jenkins jenkins 2010 Sep 9 05:00 installedPlugins.xml