problem with yum - fedora core 7

[Fernando Takai]

hi!

i've just updated my fc6 for my fc7 and yum is not working!

when i type anything, like yum list, or yum install <package> it gives 
me this error message:

Loading "installonlyn" plugin
Loading "kernel-module" plugin
Traceback (most recent call last):
  File "/usr/bin/yum", line 29, in <module>
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 94, in main
    result, resultmsgs = base.doCommands()
  File "/usr/share/yum-cli/cli.py", line 264, in doCommands
    return self.yum_cli_commands[self.basecmd].doCommand(self, 
self.basecmd, self.extcmds)
  File "/usr/share/yum-cli/yumcommands.py", line 160, in doCommand
    ypl = base.returnPkgLists(extcmds)
  File "/usr/share/yum-cli/cli.py", line 771, in returnPkgLists
    ypl = self.doPackageLists(pkgnarrow=pkgnarrow)
  File "/usr/lib/python2.5/site-packages/yum/__init__.py", line 1048, in 
doPackageLists
    avail = self.pkgSack.returnNewestByNameArch()
  File "/usr/lib/python2.5/site-packages/yum/__init__.py", line 501, in 
<lambda>
    pkgSack = property(fget=lambda self: self._getSacks(),
  File "/usr/lib/python2.5/site-packages/yum/__init__.py", line 382, in 
_getSacks
    self.repos.populateSack(which=repos)
  File "/usr/lib/python2.5/site-packages/yum/repos.py", line 206, in 
populateSack
    sack.populate(repo, mdtype, callback, cacheonly)
  File "/usr/lib/python2.5/site-packages/yum/yumRepo.py", line 160, in 
populate
    dobj = repo.cacheHandler.open_database(db_un_fn)
  File "/usr/lib/python2.5/site-packages/sqlitecachec.py", line 31, in 
open_database
    con = sqlite.connect(filename)
sqlite3.OperationalError: unable to open database file

i've tried everything, including deleting all the repos and getting them 
again.

does anybody nows what is going on?


thks!!!

Fernando Takai.