For some odd reason, my iPhone 4 doesn't ring/vibrate when a new text comes in. This doesn't happen very often but it does happen couple times a day. Which is weird. Anyway, I normally have my iPhone set on silent, so it's just the vibration, and like I already said, it doesn't always vibrate. But then I switched it from that to the ring/vibrate mode and it still doesn't always vibrate and ring. Anyone else having this issue? Is there a way to fix it?
I had that on my 3GS so switched the texting tone for awhile and it worked again. Not sure about it not vibrating...
I noticed my phone do that today too. It was in front of me on my desk and I watched as the light from the screen turned on but there was no noise or vibrate. Picked up my phone and I had an SMS. Checked and it wasn't set to vibrate mode but normal mode. Got another SMS later on and there was noise and vibrate. Strange Mine is a 3GS btw