IOS App Icon Problem

It is my first time to develop for iOS with corona and I am having a problem about the app icons.
My icons are having a black border , even though I am using transparent image files. Same problem for iOS 7.
Here is my sample screen shot:

Any help would be greatly appreciated. thanks!

Hi Fidelis,

Icons should be png files but with no transparent area (alpha channel) and it should be square not rounded edges.

Rounded edges is automatically created. 

burhan

Hi Fidelis,

Icons should be png files but with no transparent area (alpha channel) and it should be square not rounded edges.

Rounded edges is automatically created. 

burhan