I have this same problem with facebook. I live in Tokyo and my facebook keeps coming up in Japanese no matter what I do. I understand Japanese sufficiently to handle the problem, but it annoys me nonetheless. I've had this problem also with other programs; for example, my hotmail account. I wasted countless hours trying to get this problem fixed. I finally switched to gmail where I was able to find a fix. These programs must assume that we are literate in the language of the country where we happen to be.