I am having the same problem and I think he needs a little help explaining it. When I add media and insert an image, if I use the thumbnail selection from the drop down menu before inserting it into the post, it crops the width, so to remedy this, I choose the medium size which does not change the height/width ratio, then I click on the image in the post so there is the marquee, or squares around it to drag it larger or smaller.
I hold my shift button down and re-size the image , say to 150 height without loosing my width ration and save the page.
the issue is when I view that page, even though in firebug is says its the correct new width, it isnt, it shows on the page as the medium or original size, the re-size does not reflect on the front end, something is wrong with the way it is showing images placed in a page.
Is that a better way of explaining it?
look at this page:
and look at it in firebug, you will see that the dimensions for the larger inserted images are not the same as they are showing on the page. in the dashboard page WYSIWYG editor, the image is smaller, much smaller than it shows on the front.