yeah mine does that too, it is busy going back to the menu and keeping the address book open in the background for a sec then it goes to close it. if you want to leave the address book open just hit menu twice and it will get you there quicker and you can leave stuff open in the background. if you leave too much open then you can get out of memory issues but it helps when you are jumping around copy and pasting and browsing and everything.
or listening to music in the background that is cool too.
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