*UPDATE* I had this happen to me when I put a full backpack in my backpack or something similar. Because the backpack only takes up like 20 slots in the inventory yet holds 35; I thought it was ingenious to store my backpack full of rations in my backpack. It seems like doing this for extended periods of times can desync you.
While looking in my player profile (in the Day Z directory) I noticed it might be because it doesnt actually save the contents of the bag within a bag.
Solved the problem by dropping anything that used the exploit, or "bagception" as I had termed it, and joined another server.