This is in reference to the showcase theme, WP single user 3.0.5, CentOS server 5.5, latest everything.
Site can be seen here: www (dot) adventure-panama (dot) com
First, let's be blatantly clear on something - if theme is set to WP Twenty Ten, there is no issue. The issue only arises when theme is set to Showcase - a theme purportedly designed for images. Also, I am fully cognisant of aspect ratios, and how to maintain them correctly - I've been taking, processing & working with images for 20 years.
Post where issue is seen - Panama Canal Tours - notice how all the images have that lovely vertical stretch to them? Everything is tall and thin - great if you are photographing short, fat people. Anything else, not so much.
The original images are 1000x667. Since Showcase is a very vide 1 column theme, I decided to upload the images (using the WP internal media handler / gallery - NextGen is NOT installed) with the radio button "original" checked.
The uploaded images look great, and appear undistorted if you click on them to view in single image mode. But when the images are displayed in the post, they are scaled to 640x667 - which unto itself is not a terrible thing. BUT, when the scaling is NON-proportional, it is completely inexcusable for an image / gallery oriented theme.
1) Fix you code to display image in their original aspect ratio.
2) Or, alternatively, indicate the correct method to insert images into this theme without it distorting the images with it's own non-proportional scaling.
If it's 2, then you should have configuration notes indicating the limitations of the theme. For a premium paid theme such as this, it's completely unacceptable to have to second guess the designer on how to operate the theme for maximum efficiency and results.