I just migrated to my new comp from 10.6 and now I have 2 different administrators and it made me change the name of my new profile. Is this a problem?
Are you saying you used Migration Assistant? It sounds like you setup a new account in Mountain Lion then after that used Migration Assistant to import the same account and now have two accounts with the same name, hence the required name change. Does this sound like what you did?
If so, what I would do is create a new admin account and call it "temp" or whatever. Then login to that account and go in and remove both the other accounts and when asked delete all data from the accounts. This will get you back to a fresh machine just the new, virgin temp account.
Now while in the temp account, start Migration Assistant and import everything from your old machine or old backup. that will bring your original account and its data into the new machine.
Now logout of temp and into your old account (now on the new machine) and after verifying everything is working okay, delete the temp account and its data. Done.
You might be able to get away with just the renaming the account and running with it, but I am concerned you may have permissions issues and also concerned about which if these two accounts to tell you to delete. The method I described will get you where you want to be for sure.