AirTunes sucks...
...AirTunes simply does not work. I tried everything. While the stream runs on the computer, the stream stops on the connected AirTunes devices. It is completely erratic and independent of the computer I use. When I go crazy I reboot everything, reset the PRAM and start the computer again. Then it will go for some short time and then it will start again: Music transmission stops, starts, when I stop and start iTunes loud cracking noises in the speakers (that will eventually ruin them), it will play for some time and then stop again.....
In the end there are many issues with iTunes and Airplay. One could think the software was done by Microsoft.
Ah well... if anyone has a clue how to get AirTunes to play I will be thankful, obviously Apple is not capable to.