I read in others thread that it will take some time. In fact this problem appear yesterday and I waited 1 whole day, then before posting this, i restart the whole server, try empty the recycle bin again. and waited some time but no luck. Should I delete it from the mysql db instead?
No. Maybe the daemon process died. Please run: /etc/init.d/ispconfig_server restart and then check again a few minutes later. If this does not help, please post the linux distribution and version you are using.