While having your programs running in the background allows you to multitask and reload the same apps, it is inevitable that one of these background apps may get damaged and crash. If this happens, your other programs and system operations are likely to be affected as well. That's when applications go wild or your iPhone starts acting strangely. Try closing all of your background programs to be sure this isn't the source of the problem. This will also free up some space in your iPhone's internal memory, which will help it run faster and more efficiently. Here's how you do it:

1. Press the Home button twice quickly (double-tap). If you do so, the applications viewer screen will appear with a loss of recently used apps.
2. Swipe your finger up on each app previews to clear/close them.