I worked on this map since the snapshots before 1.8 got released (which is nearly a year ago now) and have had no problems until recently. Whenever I switch from Creative to Survival and destroy a block (a pumpkin or a block of wood as an example while testing the map), I go to break a block and the block disappears and drops no item instead. I have been playing and making the game in Creative mode mainly and using just the Optifine 1.8.1 mod or 1.8.7 version. I have also been using MCEdit 1.3.3 in various places. It may be a problem from the game but it might also be a clash with one of the above tools