Hi Marco ,
Please go to SMICM ( Goto TraceFile - > Display all ) and post the error if any ( Restart the ICM if you made any changes )
As you have said you deleted STUSTSSO2 make sure that you delete the system PSE from 001 and also check in 000 .
Check you have completed the step "System Preparation" ( Check Installation - > Check Profile parameters ) , Restart the Solution manager if you made any changes
Check for any errors in transaction SECSTORE
And try again SSO setup from "Basic configuration"
Thanks ,
Manu