If you got similar error to this:

error: skipping * - transfer failed - Unknown or unexpected error
warning: u 0x874c6c0 ctrl 0x874da50 nrefs != 0 (* http)
I got it too when tried to download & Install 32bit CentOS 5.x repository by command You can try to solve this by first downloading the .rpm file using whet and then installing. I did it like this:

cd /etc/yum.repos.d

wget http://domain/filename.rpm

rpm -Uvh filename.rpm
and it worked