I'm not sure if anyone else has had this problem yet, but I haven't been able to get Air Tunes to work since I installed iTunes 10 on our MBP's. I have an Airport Extreme and two Airport Expresses. Normally I can stream music from either MBP to the Airport Expresses, but I now get errors when I try to hook up the stereos connected to the Airport Expresses. I have powered off and rebooted the AE's. When that didn't work I opened Airport Utility and unchecked enable Air Tunes and rebooted again. When that didn't work I restored to factory settings and then went through and reprogrammed the AE. Still nothing, has this occurred with anyone else? 