When I first got this computer, and I encountered and solved my first problem with the wireless networking base station, I marvelled at how I was able within iTunes to stream my existing music library from the old computer, via a 10Mb Ethernet cable to the wired DSL Ethernet router, a 100Mb cable to the wireless base station, and the air between that and my PowerBook. Shortly thereafter, I lost that capability; nothing I tried would make iTunes see the older computer.
I took some time out today to diagnose this problem, and it didn't take me long to figure out what was actually preventing iTunes from sharing between the two computers. When iTunes version 4 was initially introduced, it let users make their entire music libraries available for streaming to any other Internet-connected computer in the entire world. The users quickly caught on and developed a new method of file sharing, which piggybacked on this "streaming" system. For a time, it was good. Until, of course, Apple realised what was going on and disabled the networking features in an incremental update.
With version 4.1, sharing was reintroduced but restricted to machines on the same subnet. A quick comparison between the two Network System Preference panes revealed that the two laptops were indeed on different subnets, but it took me a bit more digging to find out why. Turns out I had for some reason activated the wireless base station's own DHCP server, which was forced to operate on a different subnet due to the wired router's existing DHCP pool. A quick read and re-read of an Apple Discussions thread made me realise this.
When I restarted the new PowerBook, I found myself unable to access my wireless network. So, I plugged directly into the Base Station and it told me to update the station's software. I did that, and everything was OK again. I disabled the Base Station's DHCP, and voilá! My PowerBook was back on the same subnet, the iTunes brothers could see each other, and everything was peachy.
Unrelated to this networking problem is one created by Virtual PC. The way Virtual PC gives its "virtual machines" Internet access is by sharing the host computer's connection via its own firewall. This means that while Virtual PC is running, Mac OS X won't let me configure its built-in Firewall because "Other firewall software is already running". I suppose I can live with that.
In other news, I have a ticket to see tomorrow's initial 2pm showing of The Matrix: Revolutions, and I intend to use it. I hope to share the (spiritual?) experience with others who'll be watching it at the same time as me; I know asciident is dragging supersat out to the 6am showing somewhere in Seattle. Anybody else planning an early or late start to see this first synchronous showing?