No mobs spawning at night or in mob spawner and only sheep spawing in old worlds. This is only happening in worlds built before 0.8. New worlds built in 0.8 spawn very few mobs and I havent seen a creeper yet after three nights in a new world.

I expected...In my old worlds- I would have mobs to fight, new animals would spawn over time after killing them and my mob spawner would have mobs dieing in it. In new worlds- All mobs would spawn in darkness and many of them as usual.

What happened...In my old worlds-No mobs spawn ever, anywhere...so my mob spawners dont work anymore. After killing all animals in the wild only sheep respawn and very few. In new worlds- Very few mobs spawn and I havent seen a creeper in three full game nights.

1. Load old world....
2. See very few animals only sheep...kill them and only sheep respawn
3. Wait for night or find darkness....
3. Wait for morning or explore in darkness...
4. See no mobs.

1. Load new world...
2. Wait for night or find darkness...
3. Run around and see a few mobs are running around...
4. Run around killing zombies, skeletons and spiders....no creepers

Samsung Galaxy Note 10.1 MCPE 0.8.0 Build 3