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/fedora/linux/9/i386/freshrpms/repodata/primary.sqlite.bz2: [Errno -3] Error performing checksum
Trying other mirror.
primary.sqlite.bz2 | 119 kB 00:04
http://ayo.ie.freshrpms.net/fedora/linux/9/i386/freshrpms/repodata/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
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
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。