Exp 0.50.125214 Bug.
When items are dropped from a player inventory, around 50% of the time, the item becomes invisible for all players on that server. Leaving the server and rejoining results in the item being visible again, but only for the player that left and rejoined.
Myself and a group of friends tested this on Exp 0.50.125214 last night. We dropped items one at a time, all different items, and around 50% of them became invisible when dropped.
This bug does not seem to be confined to particular items or areas of the map. Test was performed in a number of different areas including, roads, buildings, fields, forests, on stairs... e.t.c all items were affected.