Depending on people's ISP, some take longer than other to refresh the DNS list.
Basically, your internet service provider needs to get the updated addresses regularly. But how regularly they do it, is up to them. If they don't update it as often, then the url airsoftcanada.com will still point to the old (and busted) server. Until they refresh the list, they are out of luck, unless they go to a computer using a different ISP.
It should resolve itself within the next day or two. Generally, 48 hours is all that is needed.