The score in the SSL server test is capped to A- when older browsers are not supported (server drops connection). The reason given is "The server does not support Forward Secrecy with the reference browsers. Grade reduced to A-". However, on these clients, if the server is dropping the connection then there is no security danger. It just means that the user will have to upgrade their client to connect.
For an example, see SSL Server Test: demo.peergos.net (Powered by Qualys SSL Labs)