If I download and set the wallpaper from an app like zedge the wallpaper looks fine. If I pick am image it makes me crop it to s rectangle that doesn't fill all of the screens.
It has all different options. I've even been able to use scrollable wallpaper option again in Go Launcher without having it cut off the wallpaper on each side.
QuickPic handles this for me. It adds itself to the list of wallpaper options (gallery, live wallpapers, wallpapers, QuickPic Wallpaper) and can also act as a fast gallery replacement (w/o searching for DLNA servers!).