There is no "curse." Britney has the largest core fanbase out of anybody still releasing music and they tend to buy her stuff the first week it comes out. However, she has almost no casual fanbase anymore which is why her songs plummet afer the first week.
She isn't local at all, she's just less popular in Europe, mostly, then she used to be which is obvious. She needs to do a little promo campaign there if she want to refresh things up.
