I had similar issues - 'Errno -3' - but solved them with the following three actions.
edited /etc/yum.conf
replaced the line
http_caching=packages
with
http_caching=none
under the [main] section, saved and exited, then ran
yum clean all
followed by
yum check-update
voila - 74mb and 64 packages pending!
( I ran yum check-update before the yum clean all - but got some 'Errno -1' messages, but the clean all sorted them out and everything was tickety-boo again)