Zabbix Log Monitoring – Duplicate alerts

I am configured Zabbix to monitor my Jboss Server logs for Erros and exclude some know errors.
This setup is working, Zabbix will send me alerts when there is a new "ERROR" entry in the log file, but with one issue,
sometimes I get multiple alerts for the same event.
For example, I got 5 alerts with the same time stamp "2012-06-25 07:55:56,864 ERROR".
The duplicate alerts count is not constant, sometimes I get 2, sometimes 5 or 11.

I checked the Monitoring > Latest data in the GUI, and found that there are no duplicate entries.

My configuration of the log monitoring is below.
I am using the latest version of zabbix server(2.0)

Item configuration:

• Description: Server Error Monitoring.
• Key: log["/SERVER/jboss/jboss-5/server/ps/log/server.log","ERROR",UTF-8,200,skip]
• Type: Zabbix Agent (Active)
• Type of information: Log
• Interval :30

Trigger configuration:

• Description: Found Error in Server Log.
• Expression: (({SERVER Error Monitoring - PS:log["/SERVER/jboss/jboss-5/server/ps/log/server.log","ERROR",UTF-8,200,skip].regexp("can not execute")})=0) & (({SERVER Error Monitoring - PS:log["/SERVER/jboss/jboss-5/server/ps/log/server.log","ERROR",UTF-8,200,skip].regexp("Unexpected redirect")})=0)
• Event generation: Normal + Multiple TRUE events

Action configuration:

• Name: alert mail
• Event source: Trigger
• Enable escalations: Uncheck
• Default subject/message: Default
• Recovery message: Uncheck
• Action conditions: Trigger value = PROBLEM
• Action operations: Send message to User "Admin"