Heres my similar issue
http://scn.sap.com/thread/3790372
OK I found a workaround for my case.
See I knew all along that the issue resided with my SSL key and a trust between SUM and my PSE on the server.
But I wanted the freedom of not using SSL for SUM regardless if my server is configured for it.
So here is what I did.
I was using SUM SP13 PL06.
I downgraded to SUM SP11 PL03.
So at this point,
Open the jump_config.txt file contained in the
\usr\sap\SUM\sdt\param directory
Edit the last parameter value (/sapstartsrv/httpsconnection)
from true to false and execute the step again.
It then prompts you for the SIDADM and password and moves.
The difference between the two SUM tools. SP 13 would not take this parameter change and also it prompts for the SIDADM/Password first then does the check, where in SUM SP 11 it checks first, takes the override parameter then asks for the password.
Also, you must have this setting in your profiles service/protectedwebmethods = DEFAULT
So now I can continue without SSL in SUM.