Why does my iPhone4 vibrate twice when I get a text message?

[Jonet H]

Whenever my phone is asleep/locked and I get a text, it vibrates to let me know. But if I don't unlock the phone to read the text it will vibrate again a couple seconds later making me think I've received another text but the same one shows up on the screen. It's like it's reminding me that I have an unread message, but it dupes me into thinking I've received another new message and some times I have but most of the time I don't. Not sure when this started happening but it's really annoying, how can I make it stop doing this?

[Mr. Talk]

You just have to see through your settings. - or yo can download a nice tone so its not annoying. Your younger brother may have played with your phone, or somebody else did. Usually its just settings, try loading the default settings and see if it still does that.