Got my new 15-inch aluminium Powerbook yesterday – and returned it today. The machine puked its memory. Freezes. Panics. Unusable. This is what Apple calls D.O.A. – dead on arrival. We tried many different memory modules but either they led to immediate freezes or were not recognized at all. Everything else seemed to work fine: AirPort Extreme fetched data with 2,7 MB/sec and I never had any network dropout throughout my flat. The titanium Powerbook lost its signal if you were talking too loud, as it seemed. Stability has increased as well, the screen no longer touches the keyboard when the lid is closed and general IO throughput seemed to be boosted across the line. Hope I can continue my tests soon.