Ok, I'm not sure if you are aware of what I mean by Double-Input Lag. Basically, I right click once, a millisecond of lag, and it places 2-3 blocks. This happens the same when breaking a block. To note: It only happens it certain areas.
These forum posts should help you understand:
The list goes on. I can provide video footage if it helps. It only happens in certain places, I'm putting my money on some kind of light-rendering bug. Perhaps a lag in the last tick of placing a block meaning the click carry's on, forcing another blocks to be placed.
Thanks a lot,