Re: When I try to use the clone stamp another layer of my picture is copied on the photo I'm working on. Is this a defect or is there a tool I can use to stop it and return to normal usage of the clone stamp?

When you have the Clone Stamp Tool selected, look in the Options bar up near the top of the Photoshop main window...  What's the Sample:  field set to?

You'll need to set it to "Current Layer" to have it only sample pixels from your current layer.

-Noel