1-Wire, DS18B20... How do I search the bus?

What's the bug? Where's it detailed? I ran into a problem where I was unable to resolve more than three devices on the bus, but I thought that was due to a poor wiring job on my part (I have DS18B20s running all over my house with some hefty wiring runs). I was getting CRC errors when scanning the bus. Is that what's happening here? I see that the sample code above isn't performing a checksum...