Summary: Many apps can perform time-consuming operations on launch. For example, if you click a URL in Mail.app, Safari will load the URL on launch. If you double-click an xcodeproj file, Xcode will open the project on launch. However, on Leopard and later, if an app performs a time-consuming operation on launch, and you switch to another app while that's happening, then when the now-inactive app is finished launching, its window can appear in front of the key/main window of the active app, even though the active app's window still responds to keystrokes. This behavior is both very annoying, because the stuff that you're doing is now obscured by an inactive app's window, and very confusing, because unless you look in the menu bar, you can't be sure which app is active. The bug is particularly problematic if you have applications or files set as login items, because you'll log in, go about your business, and then suddenly inactive windows start popping out in front. Steps to Reproduce: 1. Unzip, open, and build the sample Xcode project FrontWindowBug. 2. Double-click FrontWindowBug.app in Finder. 3. Click on the Finder window to switch back to Finder from FrontWindowBug. 4. Wait a few seconds. Expected Results: FrontWindowBug's window appears behind the key Finder window. Actual Results: FrontWindowBug's window appears in front of the key Finder window, even though Finder is still the active app, and the Finder window still responds to keyboard input. Regression: This bug does not occur on Mac OS X 10.4.11. Notes: Attached sample Xcode project "FrontWindowBug.zip" that demonstrates the bug.