[MadlyAlive]

This process also worked for me (had to call Sprint the night I bought the phone from BB to do this).

Call Sprint and they'll walk you through editing the profile.

From the phone menu: ##3282#
Click Edit
Enter in your MSL Code (you'll need it from Sprint)
Under Active Profile, change from 0 to 1
Click OK and Save. Device will soft reset.
Then go to Start, Settings, System and choose Update Profile.

Once it's complete it will tell you that no update is available, but try the Internet and it will work.