ubuntu update error

W: Failed to fetch bzip2:/var/lib/apt/lists/partial/debian.ustc.edu.cn_ubuntu_dists_raring_universe_source_Sources Hash Sum mismatch

W: Failed to fetch bzip2:/var/lib/apt/lists/partial/debian.ustc.edu.cn_ubuntu_dists_raring_main_binary-amd64_Packages Hash Sum mismatch

W: Failed to fetch bzip2:/var/lib/apt/lists/partial/debian.ustc.edu.cn_ubuntu_dists_raring_main_binary-i386_Packages Hash Sum mismatch

W: Failed to fetch bzip2:/var/lib/apt/lists/partial/mirrors.163.com_ubuntu_dists_raring_universe_source_Sources Hash Sum mismatch

W: Failed to fetch bzip2:/var/lib/apt/lists/partial/mirrors.163.com_ubuntu_dists_raring_main_binary-amd64_Packages Hash Sum mismatch

W: Failed to fetch bzip2:/var/lib/apt/lists/partial/mirrors.163.com_ubuntu_dists_raring_main_binary-i386_Packages Hash Sum mismatch

E: Some index files failed to download. They have been ignored, or old ones used instead.

这是同步交大的源到出错，换北交的描述的略有不一样
求教该如何解决

在/etc/apt/apt.conf.d/00aptitude
最后加一行

Acquire::CompressionTypes::Order "gz";

然后再apt-get update