无法下载 bzip2:/var/lib/apt/lists/partial/security.ubuntu.com_ubuntu_dists_natty-security_main_binary-i386_Packages  Hash 校验和不符
无法下载 bzip2:/var/lib/apt/lists/partial/archive.ubuntu.com_ubuntu_dists_natty-updates_main_binary-i386_Packages  Hash 校验和不符
Some index files failed to download. They have been ignored, or old ones used instead.


请问如何该怎么解决！？