Images not realized as "Image" (Solved)

[Peter2]

In the Browser, in "Details view", I have some

- Bitmaps, defined as "Bitmap Image" and not as "Windows Bitmap"
- Icons, , defined as "Icon" and not as "ICO"
- PNG, , defined as "PNG Image" and not as "Portable Network Graphics"

When I set the Filter to "Images", they are not displayed.
Why? What's wrong with them?

They can be displayed, but saving them makes problems ..

I attach some examples - maybe the mystery can be explained

[xnview]

the extensions are not good, for example the .bmp is a PNG

[Peter2]

the extensions are not good, for example the .bmp is a PNG

Thanks!