Wolffe -
yes you can run AC "on a Mac" - either with something like Parallels (which some of our clients do) or you can run terminal services and access server sessions from the Mac using CORD or the Microsoft RDC client.
I'm going to guess that GAS checked the firewall, as well as the MSSQL connection properties. If not, I would verify those first.
It appears that it runs on the AC server, so first you need to verify the server settings above.
After that, I would check the firewall settings on the clients to see if MS over-wrote AC firewall entries.
We recommend that clients never set MS for auto-update. You are signing up to the first penguins in the water without knowing if killer whales are about. Better to notice that there are updates waiting, and swing by the board to see if anyone is out-of-operation because of a MS update.
