This is my scenario:

I have 4 calculated items working fine with 0 seconds update interval and:
For item (a) 60 sec at 7,23:45-23:46
For item (b) 60 sec at 7,23:46-23:47
For item (c) 60 sec at 7,23:47-23:48
For item (d) 60 sec at 7,23:48-23:49

I have 4 triggers with information severity related to the items with function .last(0) working fine.

I have an action that executes a remote command with conditions:
(A) and (B or C or D or E) and (F) and (G)
(A) Host = "XXX"
(B) Trigger = "XXX:trigger (a)"
(C) Trigger = "XXX:trigger (b)"
(D) Trigger = "XXX:trigger (c)"
(E) Trigger = "XXX:trigger (d)"
(F) Trigger severity = "Information"
(G) Trigger value = "PROBLEM"

And this is the remote command executed on host XXX

{HOSTNAME}

: /etc/zabbix/externalscripts/cuadroMando.sh

{ITEM.LASTVALUE}

{TRIGGER.NAME}

.txt

Right permisons and owner applied and I can see triggers on Dashboard with Action columns as "-".

The weirdest thing is that it has worked twice from may be 30 tries.

Tested with a comand like: echo "It works!" > /tmp/test.txt, but it neither works.

Could be related with this other issues:
https://support.zabbix.com/browse/ZBX-155
https://support.zabbix.com/browse/ZBX-682

Commented on this forum thread:
http://www.zabbix.com/forum/showthread.php?p=77553