I recently installed NextGEN Gallery and uploaded a few images that were 800 x 600 pixels (w x h). Under Image Settings, I've also set the image size to 800 x 600 pixels. However, the image itself is being displayed much smaller. I took a screen-capture and checked the size; the photos are being displayed at a width of 625 pixels. The aspect ratio is still correct, and there appears to be enough white space underneath the image to total a 600 pixel height. I'm not sure why the images can't be displayed at 100% size.