rpm database corrupted

[Francois Massonneau]

Hi,
Today, when I wanted to run a "yum update", I 've got the following error :
rpmdb: PANIC: fatal region error detected; run recovery
error: db4 error(-30977) from dbenv->open: DB_RUNRECOVERY: Fatal error, run 
database recovery
error: cannot open Packages index using db3 -  (-30977)
error: cannot open Packages database in /var/lib/rpm
Traceback (most recent call last):
  File "/usr/bin/yum", line 27, in ?
    yummain.main(sys.argv[1:])
  File "/usr/share/yum-cli/yummain.py", line 75, in main
    base.getOptionsConfig(args)
  File "/usr/share/yum-cli/cli.py", line 170, in getOptionsConfig
    self.doConfigSetup(fn=opts.conffile, root=root)
  File "__init__.py", line 82, in doConfigSetup
  File "config.py", line 271, in __init__
  File "config.py", line 383, in _getsysver
TypeError: rpmdb open failed
[root at celtes5 rpm]#       

then I wanted to run a : rpm --rebuilddb, but I got this error too :
[root at celtes5 rpm]# rpm --rebuilddb
rpmdb: PANIC: fatal region error detected; run recovery
erreur: erreur db4(-30977) de dbenv->open: DB_RUNRECOVERY: Fatal error, run 
database recovery
erreur: ne peut ouvrir l'index Packages en utilisant db3 -  (-30977)
[root at celtes5 rpm]#      

then I tried to move the files /var/lib/rpm/__db.000 __db.001 __db.002 
__db.003 I found there, (I wanted to keep them in case I need them), and 
tried to run a "rpm --rebuildd" again. 
Same error. I tried a second time, and then it created only three files 
"__db.00x"
But now it seems the database doesn't included the rpm files I added after I 
installed my FC4  a few months  ago.

What can I do to get my system as it was before this problem. ? Thanks. 
Francois