Apple iphone 4 & 4s No sound or vibration notification for waiting call.

[Ayize]

I am using apple Iphone 4 and 4s. For new incoming call there is no sound, vibration, notification. So I am unable to notice that new call is coming. What can be a solution? Please help me to solve this question.

[Saleem's]

I am having same problem. I am using Iphone 4 from two weeks. There is no sound or vibration in phone during new incoming call. When new call comes then only light starts but no vibration or any notification So I need to check several times whether new call coming or not. It’s very annoying for me. Sometimes I missed the calls because of this problem. Please help me. Any help would be appreciated

[Ekon]

I have notice my phone does same thing. This is very annoying this phone does not have any special feature for call waiting. I am very frustrated with this problem. I am really not happy with my phone because of this problem. Any help would be appreciated

[Omarr]

I am having the exact same problem. I have also updated my operating system to iOS 5 I update my phone. I am using latest version of software. I also restart my mobile several times but no effect, also done with the restore factory setting. I have also done that service update a hundred times now I am not able to figure out a way. I search internet for this problem but cannot find any solution. Can you tell me how to solve this problem? I am disappointed with this issue. Does anyone know how to solve this?

[akkiiii]

Serveral users of iphone 4 and iphone 4s have same problem with their phones. Wait for the new updates which are coming soon. I hope this updates will be available for you soon.