Since the 14 upgrade, I am having periodic time warps. Chop a tree down, and suddenly you are two steps away, and the tree is all back in place. Mine 7-8 blocks of stone, and "Poof!" it is all back in place. I have had lag cause a block to take a second or two to actually break after the breaking sound, but this is the first time that the game has moved me back 8-10 actions into the past. I am wondering if this is a new form of lag (Hoping for Optifine for 14 soon), or something else.
The Meaning of Life, the Universe, and Everything.
This is an old form of lag. It's called rubberbanding, and it's when the client and server aren't in sync. If this occurs in multiplayer, it has to do with poor connection or the server being overloaded. In singleplayer, try allocating more RAM, updating Java, updating your drivers, and/or closing other CPU-intensive programs.