yum安装过fastestmirror 之后挂了

Loaded plugins: fastestmirror, refresh-packagekit
Loading mirror speeds from cached hostfile
* freshrpms: ayo.ie.freshrpms.net
* fedora: archive.kernel.org
* livna: rpm.livna.org
* updates: archive.kernel.org
freshrpms                                                | 2.8 kB     00:00     
primary.sqlite.bz2                                       | 119 kB     00:08     
http://ayo.ie.freshrpms.net/fedo ... primary.sqlite.bz2: [Errno -3] Error performing checksum
Trying other mirror.
primary.sqlite.bz2                                       | 119 kB     00:04     
http://ayo.ie.freshrpms.net/fedo ... primary.sqlite.bz2: [Errno -3] Error performing checksum
Trying other mirror.
fedora                                                   | 2.4 kB     00:00   
livna                                                    | 2.4 kB     00:00   
updates                                                  | 2.6 kB     00:00   
Traceback (most recent call last):
  File "/usr/bin/yum", line 29, in <module>
    yummain.user_main(sys.argv[1:], exit_code=True)
  File "/usr/share/yum-cli/yummain.py", line 241, in user_main
    errcode = main(args)
  File "/usr/share/yum-cli/yummain.py", line 116, in main
    result, resultmsgs = base.doCommands()
  File "/usr/share/yum-cli/cli.py", line 307, in doCommands
    self._getTs()
  File "/usr/lib/python2.5/site-packages/yum/depsolve.py", line 98, in _getTs
    self._getTsInfo()
  File "/usr/lib/python2.5/site-packages/yum/depsolve.py", line 104, in _getTsInfo
    self._tsInfo.setDatabases(self.rpmdb, self.pkgSack)
  File "/usr/lib/python2.5/site-packages/yum/__init__.py", line 576, in <lambda>
    pkgSack = property(fget=lambda self: self._getSacks(),
  File "/usr/lib/python2.5/site-packages/yum/__init__.py", line 423, in _getSacks
    self._pkgSack.excludeArchs(archlist)
  File "/usr/lib/python2.5/site-packages/yum/packageSack.py", line 391, in excludeArchs
    sack.excludeArchs(archlist)
  File "/usr/lib/python2.5/site-packages/yum/sqlitesack.py", line 39, in newFunc
    return func(*args, **kwargs)
  File "/usr/lib/python2.5/site-packages/yum/sqlitesack.py", line 1021, in excludeArchs
    cur = cache.cursor()
AttributeError: 'NoneType' object has no attribute 'cursor'

自从我安装过fastestmirror 之后，我用yum装软件时老是都出现这些东西，安装不成功。
在以前没装fastestmirror 时虽然速度只有20多kb/s，但是能用。
查了好久都不知道是什么原因，请大侠们分析一下。

如今已经有好一些国内软件源镜像了，fastestmirror 已经不太需要了。
像 163、sohu 都有 fedora 、rpmfusion 的镜像，具体配置操作看本版 FAQ 或 google