Default NB1 to MK2 Help Please

Hello Folks, I unfortunately did not see that my phone did a OTA update to the newest firmware NB1. I was running MK2 and was able to root no problems. I did n ot unlock the Boot loader yet. The issue I am having is I cant revert back to MK2 thru Odin using these instructions: Anyone have any ideas why it wont let me down grade? Is it due to the fact that I was rooted on MK2? I'm at a loss. I would like to be able to root again. Any help would be appreciated. Thanks