I have a 3030 concentrator that I have lost admin rights on due to others 'trying' to configure TACACS auth. I can login with the admin level account but I can not do any activities at the admin level (Admin | Access Rights). I want to wipe the 3030 and start over (in the lab).
You could try password recovery to see if that will restore administrative access. It might be that administrative authority has been given to one of the other default accounts on the 3030.
Once you have administrative access you can restore factory defaults by deleting the CONFIG file and rebooting.