We were getting this iTunes 8 error:
An error occured while connecting to the remote speaker “XYZ”. An unknown error occured (-3256).
We use a 3G iPhone running the app “Remote” to connect to iTunes and control the music. But we couldn’t connect to our Airport Express speakers over the wireless network.
The solution? Open System Preferences: Network: Airport: Advanced: TCP/IP, and change Configure IPv6 to “Off”.