I have a Samsung Stratosphere, running Android 2.3.6. My problem is that when I'm on the home screen and I slide the keyboard out (putting the device into landscape mode), the wallpaper does not change with the rest of screen. For the purposes of illustration, I've made a home screen less cluttered than my real one, and used a wallpaper whose orientation can be more easily discerned (see here for the full image). Click on the screenshots below for larger versions.
As you can see, the wallpaper doesn't rotate to match the orientation of the screen, nor does it stretch; there are just some (very silly looking) black bars.
I owned a Stratosphere for a few years, during which I never had this problem with the wallpaper; however, the wallpaper I used during this time was just an image consisting of just a solid color, so I can't say for sure whether the wallpaper was being rotated or stretched. All I know is that I never had any black bars. But I recently dropped it and had to get a replacement via my Asurion insurance policy, and now an ostensibly identical device has this problem. Any help would be appreciated.