eCover Wizard Pro is not software for creating covers for Amazon Kindle.
It's more of a general eCover and 3D Cover Creator. For creating covers for your reports so you can use them on your website, blog and sales pages etc.
Kindle covers have different dimensions to normal eCovers and that's why if you upload one of our covers to Amazon it may look a little strange.
We are planning to create a Kindle Cover Software which would be specifically for those dimensions and templates built for Amazon and will keep you informed of when it's ready etc.
But for now you can simply open your Flat eCover on your computer and resize it so it has a minimum height of 1000 pixels. Then you can upload it to Amazon and use it for your Kindle cover.