I maintain reposyncs of all upstream repos, and the zabbix-non-supported repo has (most likely) a mistake:

1. repoquery -qa --repoid=zabbix-non-supported
   fping-0:2.4b2-16.el6.x86_64
   iksemel-0:1.4-2.el6.x86_64
   iksemel-devel-0:1.4-2.el6.x86_64
   iksemel-utils-0:1.4-2.el6.x86_64
   libssh2-0:1.4.2-2.el6.x86_64
   libssh2-devel-0:1.4.2-2.el6.x86_64
   libssh2-docs-0:1.2.2-7.el6.x86_64
   libssh2-docs-0:1.4.2-2.el6.noarch
   zabbix-release-0:2.0-1.el6.noarch

Note the zabbix-release RPM is out of date and is not available from the baseurl anyways. Since it's older than the version available from the normal zabbix repo, this is a nonissue to normal users, but anyone doing a reposync like me will have a nuisance error in their cronjob logs every night.