What actually happened was...:
I re-created a map in snapshot 13w39b from a very old map (minecraft 1.2)
When i spawned in i could see item frames had spawned up in the air above me.
I could not interact with these frames at all. they were there but i could not brake them or anything.
Later the same day i created a brand new map within the newest snapshot and then picture frames had spawned in above my spawn point.
again they were there but i could not interact with them in any way other that looking at them.
Steps to Reproduce:
I tried to re-create the maps with this bug on using the same seed several times and the frames were there every time i tried.
Duplicate of MC-33193 - If you have not, please use the search function in the future, to see if your bug has already been submitted. If you could not find the original report, please comment with the keywords you searched for.