Metrics Output Issue

I'm using Logstash 1.5.1 with the latest metrics plugin.
At the end of the filters section I have the following get metrics for windows accounts lockouts:

if [EventID] == 4740 {
metrics {
meter => "lockouts"
add_tag => "metric"
add_field => { "lockout_trigger" => "true" }
clear_interval => 3600

I added the add_field to test if the conditional was working.
When the EventID matches 4740 the metrics filter does not give any output and the field lockout_trigger is not created.

Can't figure out whatt the issue is.