Troubleshooting iPhone apps that quit unexpectedly

Are you having problems with apps that close unexpectedly on your iPhone or iPod Touch, returning you repeatedly to the device's Home screen? Apple has detailed both the cause and the suggested cures in a new knowledge base article.

According to Apple, the primary cause for apps closing unexpectedly is a device running low on memory allocated for applications--a bigger problem on the original iPhone and the iPhone 3G, since each had only 128MB of application memory. (The iPhone 3GS was released with 256MB.) The problem has nothing to do with how much data is stored on the device, since that memory is allocated separately. The device is simply running too many memory-intensive tasks, thus consuming all the available application memory.

Apple makes the following recommendations to avoid the problem:

• Make sure that your iPhone or iPod Touch is running the most recent version of iPhone OS. Currently that is 3.1.3 and you can check by launching Settings > General > About > Version.
• Turn your device off and on by pressing and holding the Sleep/Wake button until the red slider appears and then slide it. The device should power down. Press and hold the same button until the Apple logo appears to turn it back on. Now launch the problematic app again.
• If the problem happens while you are using Mobile Safari, minimize the number of pages/browser windows that are open by closing them.

If none of these work, we offer the following additional suggestions:

• Reboot your device by pressing and holding Sleep/Wake and Home buttons for about 10 seconds until the Apple logo appears and release both. Now launch the problematic app again.
• Delete the App from your iPhone or iPod Touch. Reboot the device as detailed above, then download the app from the App Store again or re-sync it in iTunes from your computer. Now launch the problematic app again.

Generally, this problem isn't a hardware issue, so replacing your device won't resolve the issue. If the steps outlined above don't help, consider Apple's additional suggestions for troubleshooting apps purchased in the App Store.