Remote command is not executed

[carl_qin]

We're using zabbix server 2.0.6 and zabbix agent 2.0.6,I set up a trigger.Once event triggered,it will send email out and execute remote command to restart service.I received email but remote command never executed.From zabbix agent log,I got below information
Requested [system.run["sudo /etc/zabbix/startapp.sh","nowait"]]
Executing command 'sudo /etc/zabbix/startapp.sh'
Sending back [1]

This script works fine if executed manually.I also tried solutions in previous threads.But still unlucky.

Thanks for any help.