We suddenly started getting comments about sound not working over the last week.

An alert system to emails us if there are potentially fatal errors introduced by OS updates would be very useful in facilitating faster updates when problems do arise. cheers

Yup see the daily builds, latest one has fix

Yeah there are a few issues with iOS5 and audio.

See links:
http://developer.anscamobile.com/forum/2011/10/16/ios-5-new-sound-and-music-problems
https://developer.anscamobile.com/forum/2011/08/06/sound-not-working-latest-ipad-build

The best way to stay on top of these things is to have one development device for each OS you're supporting. On iOS I currently support iOS 3, 4 and 5, so I have devices with iOS 3.1.3, 4.3.5 and 5.0.
By having these devices and testing on each OS I'm able to detect bugs before users start bombarding me with nasty emails and/or 1-star reviews...

@ingemar

Yeah we do have development devices for both Android & iOS, but not one for each OS version. Thanks for the links!