I have an iBook G4 12" (2005, 1.33GHz, 1GB, AirPort Extreme) that keeps freezing up. I initially thought it was the HDD because while the cursor would still work, the HDD would go (mostly) quiet and nothing would open. It happened around a minute or so after starting to browse the web, often in the middle of a download. It didn't happen when I wasn't using the Internet, no matter how long the machine was on. I replaced the HDD but that didn't fix it. I eventually realized that it worked fine if I kept disconnected from WiFi, but I could use Ethernet without trouble. Yesterday I bought an AirPort Extreme Base Station (A1034) and kept it on WEP for older devices. Interestingly, my iBook could connect to this without trouble and it didn't freeze at all. My normal WiFi is WPA2 and connecting to it still causes the freezing. I used it at school today, which has an open WiFi network, and it froze then too. What's going on, and how can I fix it? I had a similar thing happen to my first-ten 12" PowerBook G4 too.