explorer folder preview image issue

Hello all! This is admittedly a minor issue but it's becoming more of an annoyance. With my picture containing folders, I like to know what's in each folder by having a preview image. The default seems to be to show a few images from the folder, which at that size is hard to see anything, so I was happy when I found I could specify to have a single image as the preview and specify which image is used for the preview by going to the customize page of the folder options. So after spending a good deal of time setting a preview image for each folder, I find that the next time I go to my picture files, explorer has reverted back to the default and has completely disregarded my choices. What's weirder is that it only did this with SOME of the folders.

I definitely pressed apply when making the changes to the folder options so I don't get why it's not sticking. Is there a way to lock in those changes more securely? It seems to remember the change short-term but if it's been a few days since I accessed the folder, that's when it often forgets my changes. I was thinking that maybe shutting down the computer after making the changes might help lock them in but I have no idea how explorer goes about saving folder options.

Thanks in advance for any help.

Thanks Jerry. I'll give this a try.