You might ask what and how does it matter if you have SSO enable or not. And how does it help in case we disable SSO. Yes it does !!!
I would suggest just try this. I have seen many occasion in my Production env giving errors for SSL handshake, each and every pointer in google or metalink is saying something is wrong with root certificate or you didn't imported your root certificate well. I tried it many times, but error remains same.
Now what, I have disabled the SSO and tried login and amazingly it was working fine. But now how to resolve the issue. While looking at certificate I reaslized one off the certificate in client end, means my System has some issue. I have reinstalled that from server and re-enabled my SSO .... vola it worked !!!!!!!
I know you might feel its imaginery situation, but it always works.
Happy Troubleshooting !!!