So i have a 250g external. This one to be exact: http://www.staples.com/office/suppl...ing-_-Technology%3EHard_Drives-_-763797-34263 and well, i've only really used up about 50 gigs with music and maybe another 20 or less with some files for school and Back Ups. Recently Time Machine started telling me my drive is getting full? But this is not true at all. I even went in and just deleted everything but my music and the space available did not change at all?? What's going on? Did i do something wrong? Should I just invest in a new drive?