I can't install ros at the first step!

edit

I follow the instruction: 1.on Ubuntu 11.10 (Oneiric)

sudo sh -c 'echo "deb http://packages.ros.org/ros/ubuntu oneiric main" > /etc/apt/sources.list.d/ros-latest.list'

2.Set up my keys:

wget http://packages.ros.org/ros.key -O - | sudo apt-key add -

3.sudo apt-get update

However ,it doesn't work:

Get:75 http://mirror.bjtu.edu.cn oneiric-security/restricted Translation-en [978 B]
Get:76 http://mirror.bjtu.edu.cn oneiric-security/universe Translation-en [45.9 kB]
Fetched 19.7 MB in 11s (1,657 kB/s)                                            
W: Failed to fetch gzip:/var/lib/apt/lists/partial/packages.ros.org_ros_ubuntu_dists_oneiric_main_binary-i386_Packages  Hash Sum mismatch

I have try to clean the /var/lib/apt/lists,but it doesn't work.

I installed fuerte several months ago,and this time I even can't install the ros!

This problem have bothered me a month....