一，温度过高
本人是原系统是Ubuntu 11.04，升级安装了Ubuntu 12.04之后，发现t400的背面中央的位置温度极高，google了一下，发现是t400的双显卡的问题，因为我安装的的win7和ubuntu双系统，win7默认开启了智能显卡切换，所以就按照默认bios设置安装了ubuntu，可能是ubuntu对双显卡支持不大好，所以才导致t400温度超高，曾经一度导致自动关机，你就知道有多高的问题，大概70到80c。
没办法只能禁用了独立显卡，重启机器在bios里面设置了禁用了独立显卡，使用独立显卡。重启之后，温度果真降了下来。比win7稍高。不过已经可以接受了。
二，挂起（suspend）无法唤醒
使用命令：sudo apt-get install pm-utils
在ubuntu软件中心里面，找到pm-utils，点开 更多信息 把其他三个没有安装的附加选项钩选上，应用设置就好了。
三，没有休眠（hibernate）选项
ubuntu 12.04 因为某些程序的bug，所以禁用的hibernate选项。说明如下：
Ubuntu12.04 (Precise Pangolin) is getting closer to launch, but some of thebugs have not been iron out yet. It seems that the Hibernate functionis one of them.
The Hibernate function won't beavailable in Ubuntu 12.04 (Precise Pangolin), at least according tosome discussions that took place on Launchpad these days, where a bugwassubmitted.
Itappears that hibernation is disabled by default in Ubuntu 12.04 andthere is no option available to enable it, unless you are willing todoodle with some configuration files.
The bug or at least thelack of this feature will affect all of the Ubuntu derivatives,Kubuntu 12.04, Lubuntu 12.04, and Xubuntu 12.04.
According tosome of the comments made regarding the bug, it appears that thisfunction affects a number of users in the previous versions of theUbuntu operating system and made them lose important files.
We'llkeep you informed if Canonical decides to implement hibernate again!
一旦您和我一样，想要开启休眠选择，那么操作如下：
Enable Hibernation in Ubuntu 12.04 (PrecisePangolin)
I don’t know about you, but it seems like after upgrading orinstalling Ubuntu 12.04, the hibernation command on the session menuisn’t available anymore. The only command available to save yoursession and put your computer to sleep is the Suspend command. Now ifyour situation is like mine, and want to bring back the hibernatecommand in Ubuntu 12.04, then continue below to learn how to bring itback. This will restore the hibernation command to your session menu.Without wasting anymore or your time, let’s get going.
Objectives:
Enable Hibernate command on thesession menu in Ubuntu 12.04
Enjoy!
First, test hibernation works on yoursystem by running command:
sudo pm-hibernate
If everything is fine,you can continue to use this command to hibernate your system.
To get started, press Ctrl – Alt – Ton your keyboard to open Terminal. When it opens, run the commandsbelow to create a hibernate policy file.
sudo gedit /var/lib/polkit-1/localauthority/50-local.d/hibernate.pkla
precise_hibernate
Then copy and paste the lines below into the file and save it.
[Re-enable Hibernate]
Identity=unix-user:*
Action=org.freedesktop.upower.hibernate
ResultActive=yes
Restart your computer and you should see it.
Enjoy!