Despite the care we take to test isos for new versions of Mageia, we missed a potentially huge bug… It concerned the isos using the classical installer. If the user chose to add online media at the beginning of the installation, it would result in the system being updated to Cauldron, the development version of Mageia. This was due to the initial isos including a partial misidentification, referring to the development version (and not the Official one). The update media added pointed to Mageia Cauldron and not to the Mageia 3 repositories. Please note that users who chose to add online media only at the end of the installation would not be affected by this problem.
Read the full thing at http://blog.mageia.org/en/2013/06/09/new-isos-available-for-mageia-3-classical-installer/