我已按照安装无人值守升级的说明在我的服务器（ubuntu 服务器 13.10）上安装自动安全更新。
https://help.ubuntu.com/community/AutomaticSecurityUpdates
你能帮我理解为什么今天早上我的服务器上仍然有心跳的错误吗？
$ openssl version -a
OpenSSL 1.0.1e 11 Feb 2013
built on: Wed Jan 8 20:58:47 UTC 2014
platform: debian-amd64
其他信息：
$ cat /etc/apt/apt.conf.d/20auto-upgrades
APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Unattended-Upgrade "1";
$ cat /var/log/apt/history.log
....
Start-Date: 2014-04-03 15:33:59
Commandline: apt-get install nginx
Install: libxau6:amd64 (1.0.8-1, automatic), libx11-data:amd64 (1.6.1-1ubuntu1, automatic), libxcb1:amd64 (1.9.1-3ubuntu1, automatic), libvpx1:amd64 (1.2.0-2, automatic), libgd3:amd64 (2.1.0-2, automatic), libxdmcp6:amd64 (1.1.1-1, automatic), libxslt1.1:amd64 (1.1.28-2, automatic), nginx-common:amd64 (1.4.1-3ubuntu1.3, automatic), nginx:amd64 (1.4.1-3ubuntu1.3), nginx-full:amd64 (1.4.1-3ubuntu1.3, automatic), libx11-6:amd64 (1.6.1-1ubuntu1, automatic), libxpm4:amd64 (3.5.10-1, automatic)
End-Date: …