Known Issues In Airfoil

Airfoil goes through rigorous design and testing before it ever gets released. However, issues can arise which can't or won't be worked around, at least not presently. Read on for more information.
Audio Delays: Delays are inherent in transmitting to the AirPort Express. This is an issue with the AirPort Express hardware, and unfortunately there is no way around this.
802.11b: When using Airfoil on an 802.11b (AirPort) network, instead of an 802.11g (AirPort Extreme) network, remote playback may skip or stall, as the network is not fast enough to allow for proper playback. You may inadvertently create an 802.11b network by adding an 802.11b device, such as an older Mac, or a very old AirPort Base Station. If possible, set your network to only run as 802.11g in the AirPort Admin Utility application.
Fast User Switching: Because audio playback can behave in unexpected ways when switched out of an account, Airfoil is not supported for use when switching between users with Fast User Switching.