ubuntu更新エラーW:Failed to fetch

 ubuntu          ，      ，       ，       
          

        。

  ：
W:Failed to fetch bzip2:/var/lib/apt/lists/partial/extras.ubuntu.com_ubuntu_di
sts_precise_main_source_Sources  Hash Sum mismatch
, W:Failed to fetch bzip2:/var/lib/apt/lists/partial/extras.ubuntu.com_ubuntu_
dists_precise_main_binary-amd64_Packages  Hash Sum mismatch
, W:Failed to fetch bzip2:/var/lib/apt/lists/partial/extras.ubuntu.com_ubuntu_
dists_precise_main_binary-i386_Packages  Hash Sum mismatch
, E:Some index files failed to download. They have been ignored, or old ones u
sed instead.

           ，            
       

☆──────────────────────────────────────☆
     TomatoSmith ( )   2012 06 11 13:46:41    )
   ：

   /etc/apt/apt.conf.d/05aptitude
     

Acquire::CompressionTypes::Order "gz";

   apt-get update