Lightroom gallery quirk

[Orio]

I want to create a gallery in lightroom, but I don't like the way Lightroom resamples the images (you are not given the option to keep the originals).
So I did create the gallery and tried to replace the lightroom created photos with the originals. And then two strange things happened:

1- when trying to write over the images (replacing lightroom JPGs with original JPGs), Windows did not ask about "delete or rename" as I expected, since the filenames and extension were identical. Instead, it did simply copy the files without replacing, so that I ended up with couples of identically named files in the same directory. First time that this ever happened to me since I use computers.
2- the gallery pages do not load the original pictures.

So my question is, what can that be, that makes the pages not to load images that have the same name, extension, and pixel dimensions as the images created by Lightroom gallery module?

[Orio]

Would it help you tech skilled guys if I post here two identically named images that windows sees as different?