为什么禁用了Software Updater中的某些复选框？

在Ubuntu 13.04中，软件更新程序将某些应用程序显示为具有更新，但它们是不可选择的：

尚不清楚它们为什么变灰。

在命令行上：

$ sudo apt-get upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages have been kept back:
  gnuplot-nox gnuplot-x11 nvidia-current
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.

还要注意，运行apt-get dist-upgrade也不会导致它们被安装，就像有时保留的软件包一样。这是输出：

$ sudo apt-get dist-upgrade
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Calculating upgrade... Done
The following packages have been kept back:
  gnuplot-nox gnuplot-x11 nvidia-current
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.

我接受了@quidage的建议，它给出了以下内容。但是，随后的升级显示相同的消息：

$ sudo apt-get install -f
Reading package lists... Done
Building dependency tree       
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 3 not upgraded.

The following packages have been kept back:通常意味着您具有升级而不是软件包更新。

sudo apt-get dist-upgrade

将解决此问题。它将显示以下消息...

The following NEW packages will be installed:

和

The following packages will be upgraded:

检查包裹的状态：

dpkg --get-selections | grep "name of your package"

如果显示状态hold，则无法选中“软件更新程序”窗口中的复选框。

删除hold运行

sudo apt-mark unhold "name of your package"

我也有这个：

$ dpkg --get-selections | grep "gnuplot-nox"
gnuplot-nox                 install

我所做的就是跑步

$ sudo aptitude update
$ sudo aptitude upgrade

aptitude决定卸载gnuplot-nox。之后，我必须安装gnuplot软件包。我不知道怎么回事，艰难。