Maybe it's because most of the time I'm not looking at my account from another person's perspective. Maybe it has been this way for a while. I see my uploaded, chosen background when I'm "Home" et al, using my account and posting, but when I'm looking at my account as an individual, there's a light-blue background. Has it always been this way and I just haven't noticed? What's the point in having a chosen background when only you see it?