Help Why to photos from Camera look distorted as the wallpaper?

[Terrier Hockey]

I often like to change my wallpaper to some picture I've taken recently with my Vibrant camera. However, whenever I set a photo as the wallpaper there is noticeable distortion--something that is not there with any of the stock wallpapers or photos taken with my separate digital cameras. The camera is indeed taking photos at the highest size and 5MP is plenty to fill the wallpaper, and the photos themselves are not distorted when viewed elsewhere.

Anyone else notice this?