If you put your response anywhere inside the quote tags, it will show as if your comment is part of the original post you're quoting and we need to click on the expand button and search inside the original post to see it.
If you put it outside the quote tag(before the [ quote] or after the [ /quote]), then we can easily distinguish between the two.
This seem to be a common mistake since the forum change as opposed to in the previous one, I'm not sure why since it's basically the same thing though.
It might be a temporary problem with their US server(assuming they have one), it would be surprising if they started blocking countries since they don't host any files, only links. If it persists after a couple of days, then it might become more serious of a problem.
Do you get a specific error message?