Costas,
Simply follow the steps below:

1. run admin.ppc.sys;parm=2
 Log on as admin and supply the required password if necessary. If you
logged on successfully, you would have deleted all the backlog of users
logged on.

2. run admin.ppc.sys;parm=1
Log on as admin and supply the passwords required if necessary. If you
logged on successfully, you would have started the information access
afresh.

Regards,
Ibk