after logrotate logs are empty

root@helen:/var/log# find /var/log -empty
/var/log/alternatives.log
/var/log/btmp
/var/log/auth.log
/var/log/mysql
/var/log/news/news.crit
/var/log/news/news.err
/var/log/news/news.notice
/var/log/mail.log
/var/log/syslog
/var/log/btmp.1
/var/log/ntop/access.log
/var/log/dist-upgrade
/var/log/mailman/locks.1
/var/log/mailman/smtp-failure
/var/log/mailman/locks
/var/log/mailman/mischief.1
/var/log/mysql.err
/var/log/landscape/sysinfo.log
/var/log/aptitude
/var/log/ufw.log
/var/log/apache2/other_vhosts_access.log
/var/log/mysql.log
/var/log/mail.err

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: logrotate 3.7.8-6ubuntu5
ProcVersionSignature: Ubuntu 3.2.0-25.40-generic 3.2.18
Uname: Linux 3.2.0-25-generic x86_64
ApportVersion: 2.0.1-0ubuntu8
Architecture: amd64
Date: Thu Jul 19 11:08:26 2012
InstallationMedia: Ubuntu-Server 12.04 LTS "Precise Pangolin" - Release amd64 (20120424.1)
ProcEnviron:
 TERM=xterm
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: logrotate
UpgradeStatus: No upgrade log present (probably fresh install)