Why is this cron entry executed twice?

Question

*/5 * * * * my command

This entry works but every 5 minutes it gets executed twice, why?

In /var/log/cron it shows:

Answer 1

I use OpenWrt.

I have the same problem, but I have just one cron : ps | grep crond :

31447 root      1508 S    /usr/sbin/crond -c /etc/crontabs -l 8 
31454 root      1500 S    sh -c ps | grep crond 
31456 root      1496 S    grep crond

logread | grep cron

May 27 13:15:01 decibox cron.info crond[31447]: crond: USER root pid 1594 cmd /root/check_connect.php.sh 
May 27 13:20:01 decibox cron.info crond[31447]: crond: USER root pid 2103 cmd /root/check_connect.php.sh 
May 27 13:20:01 decibox cron.info crond[31447]: crond: USER root pid 2325 cmd /root/check_connect.php.sh 
May 27 13:25:01 decibox cron.info crond[31447]: crond: USER root pid 2880 cmd /root/check_connect.php.sh