CC version 1.62
Forge 9.11.1.953

If a turtle tries to place items in a container (chest, dispenser, dropper etc) and it would have a remainder of items (ie trying to place 64 items in a container that can only hold 4 more of that item) it will fill that container, but the number of items it holds will remain the same

to see this bug, completely fill a container with an item, and take a single item out, place a turtle facing toward the container, give it at least 2 of the item (if it can drop all items it wont produce the bug) you took out of the container, and enter "turtle.drop()" into the lua prompt. you will see it returns true, it indeed drops that item into the container, but the number of held items doesnt change