I believe StevenNL2000's last comment is correct about the cause of this problem.
In my base's storage area, I have two 3-high rooms separated by a floor/ceiling of 1 block of stone and item frames on the highest block in the lower room.
Removing the item from the frame shows the item ejecting from the frame and disappearing when it hits the ground. I went and checked the upper room, and yep, there the items were, scattered on the floor. I was able to pick them up normally.
While I don't think it matters which item is in the item frame, I was working with: redstone dust, slime blocks, and slimeballs (v1.8).
Given how many votes the other issue has – yet it isn't fixed, probably because it would break a bunch of popular game mechanics – I would tend to think that this might better be fixed by adjusting the direction and/or speed the item is ejected from the item frame so it doesn't collide with the block above.
Jon Seigel
I believe StevenNL2000's last comment is correct about the cause of this problem.
In my base's storage area, I have two 3-high rooms separated by a floor/ceiling of 1 block of stone and item frames on the highest block in the lower room.
Removing the item from the frame shows the item ejecting from the frame and disappearing when it hits the ground. I went and checked the upper room, and yep, there the items were, scattered on the floor. I was able to pick them up normally.
While I don't think it matters which item is in the item frame, I was working with: redstone dust, slime blocks, and slimeballs (v1.8).
Given how many votes the other issue has – yet it isn't fixed, probably because it would break a bunch of popular game mechanics – I would tend to think that this might better be fixed by adjusting the direction and/or speed the item is ejected from the item frame so it doesn't collide with the block above.