Disappearing Thumbnail Preview Icon Image ??

[sphereboy]

I just noticed this really strange thing.

I had various images placed on my desktop. All the icons had the preview thumbnail image on them. I moved the files over to a new folder, but when I open the folder in icon view mode.. the files no longer have the preview thumbnail on them.

Anyone have any suggestions on how I can keep those preview icon thumbnails when I move those files to a new folder?

Thanks.