yum error after upgrade: Could not find any working storages.

i have a CentOS 4 box which i yum upgraded to CentOS 5, loosely following 
the suggestions at 
http://wiki.centos.org/HowTos/MigrationGuide/ServerCD_4.4_to_5.  the 
upgrade successfully completed (as far as i can tell) and i was able to 
reboot with the new kernel (a good sign, i thought).

when i try to do *anything* with yum, i get the same error.  debugging 
doesn't give me much to go on.  the output looks like this:

"[root@drogpo ~]# yum -d9 clean all
  Loading "installonlyn" plugin
  Running "config" handler for "installonlyn" plugin


  Could not find any working storages."

i found dag wieers' suggestion at 
http://www.mail-archive.com/[email protected]/msg00395.html , but i 
don't seem to have that error:

"[root@drogpo ~]# rpm -Va yum python-sqlite\* sqlite\*
  [root@drogpo ~]# "

and reinstalling sqlite anyway (on a cargo-cult basis) hasn't helped.

can anyone suggest anything else i might try, or has anyone else seen this 
problem?  thanks for any light anyone can shed.


-- 

   Tom Yates  -  http://www.teaparty.net