Apple has just released iOS 4.1 beta for developers, the new version of iOS that will likely fix many of the bugs in version 4.0 plus signal issues. For now, it is not known what this new beta version contains, but I will come back with updates as new information appears. This version is available for developers, so you don't have to worry, but I recommend you NOT to download it from the Internet and NOT to install it on your phones.
We also have a message from iH8sn0w telling us not to install iOS 4.1 beta so stay away from this new version of iOS.
UPDATED : Here are the main news from iOS 4.1 beta :
Xcode
Xcode can hang sometimes when doing a clean build if you are running on Mac OS X 10.6.3 or lower. To fix this problem please upgrade to Mac OS X 10.6.4 (Software update to Snow Leopard).
Debugger
When debugging your multitasking enabled app, avoid manually pausing and continuing from the debugger when the application is suspended in the background. Pausing an application that is suspended in the background disrupts proper multitasking behavior until the application is relaunched.
gamekit
Support for the iOS 4 preview version of Game Center will be phased out soon. Only applications that are using the version of Game Center in iOS 4.1 or greater will be supported.
*For this release, GameKitPreview.h was renamed Gamekit.h.
*The auto-matching service does not yet support player attributes. Player attributes can be used in your code but are ignored by the server.
*For iOS 4.1, the string format used by the playerID property (of the GKPlayer class) changed.
MAPK
*All MKOverlayView objects added to a map view are now composited into a single Core Animation layer. Previously each MKOverlayView had its own layer.
Nike
*The Nike + iPod application does not allow syncing workouts over the air in the seed. Syncing through iTunes works as expected.
media Player
*If your application plays background audio, it is recommended that you implement support for remote-control events to let users control the audio directly from the application switcher
UIKit
*Setting some animatable properties inside a transition animation block may not work.
*The default behavior for the new UIView block-based animation API in iOS 4 is to disable user interactions across the entire interface while the animation is playing. Developers should not rely on this behavior remaining the default as it may be reversed in future releases, thereby allowing user interactions to occur by default while the animation is playing. Programs compiled against iPhone SDK 4 will continue to work as-is, but code compiled under future versions of the SDK may require setting a different option flag to enable the original behavior.
*The default behavior for the new UIView block-based animation API in iOS 4 is to inherit the animation duration from an enclosing animation block (when present). Developers should not rely on this behavior remaining the default, as it may be reversed in future releases, thereby preventing animations from automatically inheriting the duration of their enclosing animation. Programs compiled against iPhone SDK 4.0 will continue to work as-is but code compiled under future versions of the SDK may require setting a different option flag to enable the original behavior.
