Baffled by Exif data

I'm very much in the "low amateur" range as a photographer but I still like to try to present my photos in as good a light as possible so I use an editor to pp them if I think they need it.

I'm struggling to get to grips with the complexity of Elements (7) so meanwhile I use PSP - I find it simpler to understand.

My problem is this: I cropped and resized an image to remove unwanted dead material from the edges, saved it ok without any problems. I've done this before, many times but this time PSP refuses to display the "new" image. It gives the message: "An error has occurred trying to read from the file."

Windows explorer shows that the original image is 2991kb while the new image is 5273kb. I have no idea why this should be so but I repeated the crop/resize and produced a 3rd image, size is 4780kb (minimally different probably because the crop wouldn't have been exactly the same). PSP displays this image without any problem!

So, in an effort to understand, I displayed the exif data for the three images (using Opand IExif) and can determine that there are differences between them.
Problem is, I have no idea what the exif terms mean so I co me to a full stop.

If anyone is prepared to spend the time looking at the three exif's and can explain them to me I would be very appreciative.
Can you folks read the exif data from an image I post on here?
DSC_8672 - the original image.

DSC_8672zzz - the first crop/resize that PSP will not display.

DSC_8672z - the 2nd crop/resize - PSP displays this without problem.

I would be very appreciative of anyone who can advise.

btw - Elements handles all three images without any problem. I'm definitely going to continue with the tutorial . . .

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Peter