Large images appear fine in one category but very tiny in another

First off, I don't know if this is an Easy Populate issue, Image Handler, or just a basic input problem on my end.

Problem - just uploaded 1000 items with Easy populate. The images all show correctly in the product image folder but when you click on "larger image" link, a tiny 80 x 100 pixel picture pop's up. BUT WAIT! I did this last week with Holiday songbooks and those images are working correctly when you click on the 'larger image' Since one category works and the other doesn't , I don't see how it could be an Image Handler or Easy Populate issue. I am stumped. The webiste is cheapsongbooks followed by a dot com. If you click on the Holiday songbooks, you will see the larger images appear correctly. Then, go to general songbooks, click on organ, click 'larger image' and you will see the 80 x 100 pixel image. Both of those organ pictures can be found in the images folder ... when I type www.mywebsite/images/that-image.jpg the image comes up in its full size (300 x 400). I'm hoping this is not an issue with the Preston Elite template because I really like it. Thanks again for any comments or suggestions.

More information I can provide:

Ok, the problem is not my Preston Elite template. I switched to the classic template and have the same problem with the images
I have cleared the cache from my bmz_cache but no difference

I've been working most of the day on this problem and am making some progress. I went into my admin/category to edit an item where the image was tiny. I simply re-typed the image name in the "select existing image from fileserver" field, and that solves the problem. Now the image shows up full size when "large" is clicked. Ok, well I do want to do that for 1000 images so I'm still stumped. I'm starting to think maybe I should have listed this problem in the EasyPopulate forum ?

This is some kind of cache problem. I said in my last post all you had to do was retype the image and the problem is solved. Actually you don't even need to do this. If you just go into the category item, preview it and update it, the image has been readjusted and works great. I went into the bmz_cache and deleted all the files but that isn't the problem. Thx (again)