Slow (Choppy) Rotating Beacon Block

So it seems if you power a beacon block in worlds generated before 1.0 [official release] (not sure about this, but that's what I am assuming) the particle beam effect rotates really slowly and appears choppy. Note that I am on a single player world, NOT a server. I haven't tested this on a server. I tested this on newly generated worlds and it works perfectly fine, but old world saves affect it somehow. I tried pyramids of all sizes, being in creative/survival/etc.. doesn't change a thing. Hopefully there will be a fix for this so I can use beacons on my preexisting adventure map world!

Steps to reproduce:

• Create a world
• Let it run for 60 days in real time
  or
• set the level time to 103680000 (level.dat / Tag "Time")