Yum Update Problem

[Tony Crouch]

Hi All, 
I tried to perform a 'yum update' this evening and am receiving the
following errors:

[root at localhost tony]# yum -y update
Loading "installonlyn" plugin
Setting up Update Process
Setting up repositories
http://rpm.livna.org/fedora/6/i386/repodata/repomd.xml: [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Trying other mirror.
http://livna.cat.pdx.edu/fedora/6/i386/repodata/repomd.xml: [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Trying other mirror.
http://wftp.tu-chemnitz.de/pub/linux/livna/fedora/6/i386/repodata/repomd.xml: [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Trying other mirror.
http://ftp-stud.fht-esslingen.de/pub/Mirrors/rpm.livna.org/fedora/6/i386/repodata/repomd.xml: [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Trying other mirror.
http://mirror.atrpms.net/livna/fedora/6/i386/repodata/repomd.xml: [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Trying other mirror.
livna                     100% |=========================| 1.1 kB    00:00     
http://macromedia.rediris.es/rpm/repodata/repomd.xml: [Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Trying other mirror.
Error: Cannot open/read repomd.xml file for repository: macromedia

I tried disabling the "macromedia" repoistory think it may have just been a problem with them. Doing this produces the following out:

[root at localhost tony]# yum -y --disablerepo=macromedia update
Loading "installonlyn" plugin
Setting up Update Process
Setting up repositories
Could not retrieve mirrorlist http://mirrors.fedoraproject.org/mirrorlist?repo=updates-released-fc6&arch=i386 error was
[Errno 4] IOError: <urlopen error (-2, 'Name or service not known')>
Error: Cannot find a valid baseurl for repo: updates

I am not sure whether it would have an affect (or produce this error), but this only started occurring after I physically changed the processor inside my laptop. I changed from an Intel 3Ghz
to a 2.8Ghz Celeron (I know its downgrading but there seemed to be a fault with the better processor).

Was wondering if someone might be able to shed some light onto this problem?

All the best.

Cheers, 
Tony Crouch