it is possible that they have noticed the WoW traffic and blocked it, however unless there was something in the contract when you signed up for internet access saying "no gaming" I doubt it.

Since I lack all faith in wireless networks and you say it worked fine day one, I wonder if its simply a matter of traffic. As in - now more people have moved in and set up the load on the wireless is a lot greater causing you problems.

I can't think of any software that would take a minute to kick in and then only make the connection hell rather than just breaking it completely.