Minecraft Single Player Commands Issue?

[LocoMonoco]

Hello all, i realize that mods aren't good but its not like i'm using them on Multiplayer so don't have a fit. Anyways now to the problem, i purchased Minecraft, the full updated version and everything. So i watched a tutorial on how to install singleplayer commands on my version (1.3.1) and i did it exactly how the video showed me, down to the last detail. Then i go into Minecraft and everything is all good. So i go to create a test world to see if it works. But everytime i actually start loading the world it freezes when it says "Converting World." I have tried and retried over and over again but it keeps freezing and stops responding at that point and it's frankly getting annoying. Can someone please guide me through this if you are having a similar problem? Thanks a lot to anyone who does help.

-Thanks again.

 

[iamcacao]

Why would you use mods for single player commands? 1.3.1 already has them built in!! When you go to create a world go on "more world options" and put allow cheats on. Make sure you delete your .minecraft (backup your texture packs and worlds) before doing this.