I have a related problem, but actually worse: I cannot choose any other background than one of the animated ones. I don't know how I ended up there, but neither re-booting, nor trying to select any other background (standard, or from gallery, trying different ways to open new pictures using different galleries) works for me. Selecting an animated background from an installed app works as well (I have one from a weather app) but I cannot go back to any static background picture.
As I don't know how I ended up there I don't have any tips for re-producing it - I just recall that before getting stuck with the animated backgrounds I at some time could choose one of the default backgrounds but not an own photo.
Anyone else having this problem or any tips how I could try to change to a static background again?