My assumptions would be a browser prefers to store it's downloads else where. Such as IE storing it in the documents folder, and google chrome storing it in the userProfile download folder. Could just be the browsers prefered location(default?)
My second assumption would be that the downloads placed within' C:\Users\(YourName)\Downloads\ are only available to that certain user.
And looking at it the other way around downloads placed within' Library\Documents\My Documents\Downloads could be for any user.
By no means would this be correct, haven't checked or anything. Just an idea that had came to my head when reading this topic.
My second assumption would be that the downloads placed within' C:\Users\(YourName)\Downloads\ are only available to that certain user.
And looking at it the other way around downloads placed within' Library\Documents\My Documents\Downloads could be for any user.
By no means would this be correct, haven't checked or anything. Just an idea that had came to my head when reading this topic.