Why aren't my files in acrobat ordering themselves properly?

If I have files named File1, File 2, File 3.........File10, File11, File12, when they upload to acrobat.com, they rearrange to File1, File10, File11, File12, File2, File 3....etc.

Why don't they arrange themselves into a correct numbering order?

It's very frustrating when I specifically name and number files so they're sequential, and they don't appear that way on the server.