Hi I have a 12" powerbook. I usually use airtunes, but re-did my setup and now connect it via a cable to a stereo. But the sound output is now atrocious! I think I may have a faulty headphone jack / sound-out hole in my PB. The headphones / stereo cable only seem to almost-fit. I think this is why the sound output is so poor. Do any others have this problem? Is my machine faulty? Any advice very welcome.