[CentOS] yum and /etc/redhat-release

Hi - I used yum to update CentOS 4.6.
After the reboot after the upgrade, the file
/etc/redhat-release still indicates I'm at
CentOS 4.6.

The lastest release of CentOS 4 is CentOS 4.7.

So how do I use yum to upgrade from 4.6 to 4.7?

Any help would be greatly appreciated.

-- Ken

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