Carlos,

>I created all the security tables on the Oracle database exactly as they are on MS SQL database.
>
>If someone knows how to solve this problem I will appreciate it.

Make sure you have the following tables in Oracle:

Users
UserRoles
Roles
UserSecurity
Security
RoleSecurity

If you do, then post your stack trace from the debug window so we can get a better idea of what's going on.

Regards,