Hi Bruce,
I think this is a configuration issue.
There are two ways to select Identity Providers: automatic and manual.
In the manual it will appear a screen to select it, exactly in the way that you are seeing.
You can get more information from the link below:
http://help.sap.com/saphelp_nw73/helpdata/en/94/930eb4ac7a467f99a9b54f908497a2/frameset.htm
Regards,
Hugo