Jim, you're right, some of your images look like they've been through the wringer! So I did a little more investigation and after looking at several images I've found the cause of the problem and also propose a solution.
The cause:
The IMG tag used to display images in the gallery is using width and height elements to force an image into a size of 750 pixels high by 500 pixels wide. Note that this is the classic 3:2 aspect ratio of digital cameras with an APS-C sensor.
So if your image is wider than 500 pixels or higher than 750 pixels, it will be "squeezed" to fit within the 500x750 pixel frame. This is a real pain in the neck, but there is a solution which the site designers could easily implement. That solution is to create a hyperlink to every image enabling users to click on the image and see it at the full posted size. In the interim, if you right-click on the image and select properties from the context-menu you will see the full URL for that image. You can copy this URL and paste it into the address field of your browser and click on OK (or GO). This will open the image on it's own and at the size posted.
If the site designers cannot implement such an image link feature, then there should be a caution note at the image upload stage advising users that their image should be less than or equal to 500 px wide and less than or equal to 750 px high. Unfortunately, if you're a landscape photographer, this means that your landscape format images will be rather small.
-Thorsten.