Hello, i´ve a workaround for this issue, when you use zabbix-server-pgsql:
1) apt-get install zabbix-server-pgsql 2) apt-get install php5-pgsql 3) apt-get install zabbix-frontend-php now no mysql-server will be installed, also befor you install the frontend you must install the php5-pgsql. Merry X-Mas!
