Shoutbox

Strange, mine shows pretty much all formats fine, in any of the view options.

Though, I do have a similar problem with a .exe in Documents, it will randomly change the thumbnail for the .exe every time I open Documents (though I think this is just cause the .exe is a program which just opens and immeditely closes down again ;p)

But anywho, looking at that pic, it looks like it doesn't know what program to use to display the thumbnails, kinda. Do you have any 3rd party picture viewers that you use instead of Windows Photo Gallery? - I noticed in one of the jpgs it had a thumbnail opf what looked like the Adobe Acrobat logo thingo.

Try making the default program for viewing photos WPG, if it isn't already. (right click > open with > choose default program > select Windows Photo Gallery and make sure 'Always use the selected program for this type of file' button is ticked.)

Not sure if it'll work...