Well, I guess you all have ports 3724 and 6112 open on your local machines?

It doesn't sound like a whitelist/blacklist problem, as this should just block the whole site, not just the login part?

This sort of points to some sort of problem between WOW and your school server/network?

I just have this kind of hunch that maybe there is a router there in the school system that is causing the problem?

From what I saw of the WOW website they don't "not support proxies".......... they just don't offer technical support for them? or did I get that wrong? That would seem to "let them off the hook" so to speak?

As you guys can access other games, it is reasonable to suppose that your school has no objections to them on principle........... so blocking WOW has to be some sort of error, rather than intentional?

I would very politely ( ) ask your admin to check ports 3724 and 6112 through the school system? You can block ports in the firewall, possibly in router software and also in a modern security suite? He may have missed one?

Once again, please let me emphasise that this is a mixture of pure guesswork and inductive/deductive logic this really isn't my area of expertise, so you are going to have a lot of the legwork yourselves guys