I have four triggers but only three are shown in the respective graph. The triggers are quite simple (just check if > or <).

If I disable one of the four triggers, the graph keep showing the others two plus the fourth whose was not showed before.

Maybe there's probably a hardcoded undocumented limit of 3 triggers in the graph legend, as said by richlv in http://www.zabbix.com/forum/showthread.php?s=5131971e82e33309378c011f17f9b4af&t=24696&page=2.

Tks!!