Comment 2 for bug 319301

Your Ubuntu release is no longer supported, as such it won't receive any updates.

I suppose you have upgraded since. Ubuntu 12.04LTS should have a more recent version of Zabbix (1.8.10 or possibly 1.8.11). If you could test this again and report back, that would be appreciated.

Also be advised that Zabbix developers do not monitor this bug tracker, you may wish to also file a bug report upstream at
https://support.zabbix.com/