Item Frames STILL disappearing

I put an item frame up with a clock inside it. It disappeared. I thought at first it may have fell off or burnt from being too close to a torch. I chose a new place without torches and tried again. It went missing again after a new day. No creepers about for it to fall either. All other reports say it's resolved - reporting again because it's not

Ps- I just want a wall clock... D':