Since .63 I have had issues with item usage / crafting / inventory lag. Examples include:

• Characters stops drinking even though I didn't let go of the LMB.
• Character stops reloading magazine even though I didn't let go of the LMB.
• Item will revert to original position or drop item where mouse cursor is even though I didn't let go of the LMB.
• Item will stop being crafted even though I didn't let go of the LMB.

I assume it's due to server lag. See linked video for examples https://www.dropbox.com/s/oqnmobv12jtifnt/dayz-inventory-lag.mp4