I had problems with this as well (in my case using a PC, not a Mac). I can't remember the exact nature of the problem I had, but I remember I wasn't able to use the supplied update disk either.
I logged onto Arturia's site and downloaded the update from there, and that worked. (BTW I'm on dialup, and it was still practical to download the update.) I think I did that for both the CS80 and the MiniMg, but I'm not certain.
Hope this works for you.