Hi wish i could be more help
but this is what i get when i did what you said.
there are no packages in cache to clean,i checked
this by going to cache and looking myself.i know there is no
updates needed.if there was it would keep going untill it updated or timed out with this error .
Loading "changelog" plugin
Loading "fastestmirror" plugin
Loading "installonlyn" plugin
Cleaning up Packages
0 packages removed
[root localhost ~]# yum update
Loading "changelog" plugin
Loading "fastestmirror" plugin
Loading "installonlyn" plugin
Setting up Update Process
Setting up repositories
updates [1/3]
updates 100% |=========================| 951 B 00:00
core [2/3]
core 100% |=========================| 1.1 kB 00:00
extras [3/3]
extras 100% |=========================| 1.1 kB 00:00
Loading mirror speeds from cached hostfile
Reading repository metadata in from local files
primary.xml.gz 100% |=========================| 255 kB 00:01
http://less.cogeco.net/pub/fedora/linux/core/updates/5/x86_64/repodata/primary.x ml.gz: [Errno -1]
Trying other mirror.
primary.xml.gz 100% |=========================| 224 kB 00:01
updates : ################################################## 715/715
Added 0 new packages, deleted 107 old in 0.93 seconds
primary.xml.gz 100% |=========================| 1.0 MB 00:07
http://download.fedora.redhat.com/pub/fedora/linux/extras/5/x86_64/repodata/prim ary.xml.gz: [Errno -1] Metadata file does not match checksum
Trying other mirror.
http://mirror.clarkson.edu/pub/distributions/fedora/linux/extras/5/x86_64/repoda ta/primary.xml.gz: [Errno 12] Timeout: <urlopen error timed out>
Trying other mirror.
primary.xml.gz 100% |=========================| 940 kB 00:06
ftp://fedora.mirrors.tds.net/pub/fedora-core-extras/5/x86_64/repodata/primary.xml.gz: [Errno -1] Metadata file does not match checksum
Trying other mirror.
primary.xml.gz 100% |=========================| 765 kB 00:05
extras : ################################################## 2163/2163
Added 161 new packages, deleted 849 old in 3.46 seconds
No Packages marked for Update/Obsoletion
[root localhost ~]#