Steps to reproduce the issue

1. make a clean installation from the staging code and perform the Extra Steps installing two additional languages (e.g. fr-FR and it-IT). In the Extra Steps also check the "Activate the mulitlingual feature* option, so that example categories/articles are installed too
2. set-up association between the 3 language specific categories (maybe unneded step, but no problem)
3. try to set-up association between the 3 articles (starting from the en-GB one)

Expected result

You should be able to set up association between the en-GB article and the fr-FR and it-IT articles

Actual result

when trying to set up the association for the it-IT article you are offered the fr-FR one

System information (as much as possible)

PHP Built On: Windows NT SMZ 6.3 build 9200 (Windows 8.1 Business Edition) i586
Database Version: 5.6.23
Database Collation: utf8_general_ci
PHP Version: 5.4.39
Web Server: Apache
WebServer to PHP Interface: apache2handler
Joomla! Version: Joomla! 3.4.2-dev Development [ Ember ] 21-March-2015 20:30 GMT
Joomla! Platform Version: Joomla Platform 13.1.0 Stable [ Curiosity ] 24-Apr-2013 00:00 GMT
User Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0

Additional comments

The problematic language seems to be the one with the lowest language ID
e.g. if (beside en-GB) you install ca-ES and fr-FR, it is fr-FR that becomes problematic