photo image thumbnail previews often not being updated

In Windows 7 I often see photo image thumbails in Windows Explorer that don't match the actual image, but an earlier version. This used to happen in Windows XP, but there I was able to rectify the problem by selecting the images and choosing a menu option to refresh the thumbnails. However I cannot see this option in Win7. I have tried the refresh icon at the top of the screen but it doesn't solve the problem.

So I might have a thumbnail for a photo which appears just as the full-size version does, but reduced. If I then edit the photo, say by cropping it and adjusting the colours, then saving it as a new image, it still has the same thumbnail as before!

I have noticed this problem seems to be random - sometimes the thumbnail appears correctly. Note that it appears correctly in the preview on the bottom toolbar (shown when the file is highlighted).

How can I force Win7 to refresh the thumbnails to the correct views? Otherwise it can be very confusing looking at new and old images together!

BTW, I am using Adobe Photoshop Elements 1 for my images. (Don't laugh.) I suspect this is part of the problem. I will replace it with a later version when I can.