Since Mojang's optimizations for 1.8 release, sometimes door updates and block placements do not render. The door open/closes and the blocks get placed but you cannot see the update. It takes placement of other blocks or F3+A to force a repaint and then they render. The chances are especially high when moving while opening/closing a door.
Linked issues
duplicates 1
Comments 3
This is actually a duplicate of MC-62166
I can confirm this. The updates may take tens of seconds on Intel GM965 (everything on low). This is happening with every block in the world, but TNT craters seems to be re-rendered relatively quickly (often less than 7 seconds).