Ever since I updated to v1.0.5 I have noticed an issue with the hot bar. In Creative Mode, when I am selecting new items from the master items list to put in my hot bar, if the item already exists in my inventory it copies that item into two or three different slots, preventing me from filling each slot with a different item.

For example, if I already have a repeater in my Inventory, and I choose a repeater from the master items list and place it in slot 1, it sometimes will place the same item in slots 3 and 4. The only way to fix this is to empty your inventory completely (which takes a significant amount of time). However, once you have accumulated items again, the issue comes up again.