for one of our servers I made a test grade F is returned. I have examined "SSL Server Rating Guide" and found out that this is a certificate problem. I suggest to add a quick info just like other two "Grade capped to B" - so something like "Certificate problem (maybe explaining more info what is the problem). Grade capped to F." --> because this is grade F it would be nice to have a red background color of this message.
Hope this helps improve the already excellent SSLTest.