Invalid Image apple submission process

Hi,

I have had a stressful 2 days since the project built in Unity was constantly rejected by Apple App Store right after upload. I am posting this to help people with similar problems.

This was the error message:

Invalid Image - For iOS applications, icons included in the binary submission must be in the PNG format.

If your application supports the iPhone device family, you must include a square icon of exactly 57x57 pixels.
If your application supports the iPad device family, you must include a square icon of exactly 72x72 pixels.

Turns out that there were no problem with the icon image, but with the architecture, sdk and deployment target. I had to set it to the following:
- Architecture to "Standard (armv7, armv7s)",
- Base SDK to "Latest iOS (iOS 6.1)"
- Deployment Target to "4.3", *or more recent*.

SDK and Deployment target can be changed from within Unity, but Architecture had to be changed from Xcode. And I am using latest unity 3.x build.