Hi there,
as OpenVPN 2.3 is now stable i would like to know when you update your apt repositories? As you can see here:
http://repos.openvpn.net/repos/
The date of the apt repos is 09-Jul-2012 11:18 and the date of yum repos is 08-Jan-2013 12:45. I can confirm this cause updating OpenVPN on my Debian Server doesn't work with apt-get upgrade, i'm stuck on OpenVPN 2.2.2.
A freshly install of OpenVPN on my CentOS 6 Server works with OpenVPN 2.3.
Greetz Jack