I have a Maxtor 300 gigabyte harddrive that I used to use with my Dell Inspiron XPS. I recently switched to a macbook (by the way, I love this thing to death) and when I connected the harddrive via firewire 400 it wont let me write onto the harddrive now. It says read only in the info area and I'm not sure how to change that to read & write. Please help