SSO stopped working when Radius auth is added

APM policy for SecurID and RADIUS look similar, you would have to change the logon pages and authentication objects to use RADIUS server AAA object rather then SecurID. The manual configuration section of the deployment guide deployment guide lists the various APM policy's created by the iApp (Beginning on page 62) if you would like to try the setup manually. I would suggest running the iApp using the SecurID two factor option and then modify the noted portions to use RADIUS AAA profile rather than SecurID.