The resolution of the cropping area is set to 0, 0.
The resolution to crop the image onto is set to 310, 310.
I upload a file 700 wide by 453 high.

Select an existing page. When I delete the existing image and upload a replacement, the images are scaled to the wrong size on the display. I deleted a small image and replaced it with a larger image. The new image is scaled down for both the image display and the crop.
The image is shown as 506px wide by 330px high.
The crop is shown as 232px wide by 150px high.

When I upload the first image to a new page, the display image is the right size and the cropped image is the right size.