Hi,
What Service Processor are you trying to add?
You want to do this rather from the "SP Management" Tab.
So, go to: Administration--->Extend "Targets"--->Select "SP Management" ---> Select Service Processors--->Add SP.
There enter the IP address, Make sure you enter the User name and password if it was changed from the default and uncheck "Use default user name and password"
It should then take about 1-2 Minutes and it should find the SP.
Hope this helps,
Best regards,