I've recently updated my HTC Trophy 7 to Windows Phone 7.8. Now I am able to set the bing image of the day as my lockscreen wallpaper. However, it does not change regularly. Actually it has never changed until today, since I set it for the first time. My phone has WLAN access when I am at home during night and is connected through 3G when I am away. So it constatly has an internet connection.
Is this usual behaviour? How can I tell my phone to update the image daily?