Fix outdated/corrupted EPEL repo metadata

yum update failed in RHEL (Red Hat Enterprise Linux) server 5.5 with EPEL repo added:

[root@server ~]# yum update
Loaded plugins: rhnplugin, security
Skipping security plugin, no data
Setting up Update Process
Resolving Dependencies
Skipping security plugin, no data
--> Running transaction check
---> Package cups.x86_64 1:1.3.7-18.el5_5.8 set to be updated
---> Package cups-libs.i386 1:1.3.7-18.el5_5.8 set to be updated
---> Package cups-libs.x86_64 1:1.3.7-18.el5_5.8 set to be updated
---> Package pam.i386 0:0.99.6.2-6.el5_5.2 set to be updated
---> Package pam.x86_64 0:0.99.6.2-6.el5_5.2 set to be updated
---> Package pam-devel.i386 0:0.99.6.2-6.el5_5.2 set to be updated
---> Package pam-devel.x86_64 0:0.99.6.2-6.el5_5.2 set to be updated
---> Package yum.noarch 0:3.2.22-26.el5_5.1 set to be updated
http://mirror01.idc.hinet.net/EPEL/5/x86_64/repodata/b205b049dc386d8d09316372f16b4371cef514bb-filelists.sqlite.bz2: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://ftp.riken.jp/Linux/fedora/epel/5/x86_64/repodata/b205b049dc386d8d09316372f16b4371cef514bb-filelists.sqlite.bz2: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://mirror.yandex.ru/epel/5/x86_64/repodata/b205b049dc386d8d09316372f16b4371cef514bb-filelists.sqlite.bz2: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://ftp.kddilabs.jp/Linux/packages/fedora/epel/5/x86_64/repodata/b205b049dc386d8d09316372f16b4371cef514bb-filelists.sqlite.bz2: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
http://sulawesi.idrepo.or.id/epel/5/x86_64/repodata/b205b049dc386d8d09316372f16b4371cef514bb-filelists.sqlite.bz2: [Errno 14] HTTP Error 404: Not Found
Trying other mirror.
Error: failure: repodata/b205b049dc386d8d09316372f16b4371cef514bb-filelists.sqlite.bz2 from epel: [Errno 256] No more mirrors to try.
You could try using --skip-broken to work around the problem
You could try running: package-cleanup --problems
package-cleanup --dupes
rpm -Va --nofiles --nodigest

Fixed with:

yum clean metadata
yum clean dbcache
yum update