Intel registrationcenter no longer displays the login screen properly on the old FireFox, so it's difficult to log in. After accomplishing that, there seem to be no further problems, although more tests on MIC are displaying predominantly far less than correct execution time.
I'd be happy to install a new browser, but I couldn't find any which would install on RHEL 6.2.
Maybe it's time to drop RHEL. I don't know whether to take a chance on CentOS 7.2 on such old hardware (WSM server with KNC B0 and also early Core I7 desktop).