Ubuntu 12.04 Install Mapserver 6.4 package instead of 6.2.1

Hi there,

I ´m new to Ubuntu. I´ve installed a fresh Ubuntu 12.04 Server. Now I want to install Mapserver 6.4.
For that I´ve added following two launchpad ppa´s to my sources.list

deb http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu precise main
deb-src http://ppa.launchpad.net/ubuntugis/ubuntugis-unstable/ubuntu precise main

After that following commands
$ apt-get update
$ apt-get install cgi-mapserver mapserver-bin

which results in a running Mapserver 6.2.1 Installation. So far so good, but how can I tell Ubuntu to install this
https://launchpad.net/ubuntu/+source/mapserver/6.4.0-2
Mapserver 6.4 package instead of 6.2.1

Kind regards,

berti