Hi VS2k9 (from the future right?) and welcome to our forum!
I think you may be the first person from Benin. :) Anyway, when you create a more powerful xsd using a tool like XML Spy (or notepad!) InfoPath will treat it differently, since it is "imported". InfoPath tries to preserve the structure. Any edit will result in a separate xsd being created that imports the initial xsd. This is actually good if the XSD you used in the beginning is an industry standard or something that you don't want to allow the forms designer to change since it preserves compatibility.
Happy trails!
Patrick Halstead
Project Manager at Qdabra