It did indeed used to be masterserver.cubers.net before it became what it is now. I don't remember which versions that applied to, though.
Edit: I looked into it, you're right, it was 1.1.0.4 and before that it was masterserver.cuberst.net
Edit: I looked into it, you're right, it was 1.1.0.4 and before that it was masterserver.cuberst.net