安装错误，“无法锁定管理目录”

Question

每当我尝试通过终端或软件在我的 Ubuntu 11.04 上安装任何软件时，我都会收到以下响应：

在终端：

E: Could not get lock /var/lib/dpkg/lock - open (11: Resource temporarily unavailable)
E: Unable to lock the administration directory (/var/lib/dpkg/), is another process using it?

在软件中心

An unhandlable error occured
There seems to be a programming error in aptdaemon, the software that allows you to install/remove software and to perform other package management related tasks.

我该怎么办？