items in chest disappear and paintings and item frames fall off the wall

i made a world in 1.7.5 and when i played it in 14w11b everything i had in chests were gone and the item frames i had up containing maps had dropped as an item, but yet the map was nowhere to be found. i couldn't find this mentioned anywhere, so i decided to report it. Keywords i used were: items disappear from chests and item frames fall off the wall