Hi, after having to deal with the horizontal line issue in my 15" PB now I gotta another problem with the right speaker of my Mac. The things is that this speak volumes descreases and increases randomly while the songs are playing and the same happens with some movies. Sometimes it is stable for a time but it the problems appears again. It's speaker problem because I tried with the headphones and it sounds fine. This is my third issue with my 15" PB and it only has 4 months. ¿Anyone has the same problem? ¿Any solution? I am so upset and dissapointed... Bye.