"yum update" problem in FC4

Hi,

suddenly, no more "yum update" is possible:

yum update
Setting up Update Process
Setting up repositories

Trying other mirror.
Cannot open/read repomd.xml file for repository: Extras
failure: repodata/repomd.xml from Extras: [Errno 256] No more mirrors to try.
Error: failure: repodata/repomd.xml from Extras: [Errno 256] No more mirrors to try.

/etc/yum.conf:
--------------------------- snip -----------------------
[main]
cachedir=/var/cache/yum
debuglevel=2
logfile=/var/log/yum.log
pkgpolicy=newest
distroverpkg=redhat-release
tolerant=1
exactarch=1
retries=20
obsoletes=1
gpgcheck=1
exclude=kernel* tetex*

# PUT YOUR REPOS HERE OR IN separate files named file.repo
# in /etc/yum.repos.d

[Extras]
name=Fedora Extras
baseurl=http://download.fedora.redhat.com/pub/fedora/linux/extras/$releasever/$basearch/
--------------------------- snip -----------------------

Any advice?

Regards Joachim Backes

--
Joachim Backes <joachim.backes@xxxxxxxxxxxxxx>
University of Kaiserslautern,Computer Center [RHRK],
Systems and Operations, High Performance Computing,
D-67653 Kaiserslautern, PO Box 3049, Germany
--------------------------------------------------
Phone: +49-631-205-2438, FAX: +49-631-205-3056
http://hlrwm.rhrk.uni-kl.de/home/staff/backes.html