Hi Norm, the featured image size is actually independent of the other sizes that are shown in the media uploader. The featured image is generated separately from those when you upload the image.
Most of the options in there only affect images that are added to pages or posts. You can change the title or alt text for the featured image in there, but that’s about it.
It looks like this is the image that is being used in the slide, but this is the original. Meteor Slides crops images that are larger than the slideshow, it doesn’t squish them, so I’m stumped as to how that happened!
I would suggest downloading the original, removing the featured image from a slide, updating it, and then re-upload the original and add that as a featured image and update it. See if that looks any different than the current slide.
