Just keep at the command. Keep redoing it until it sticks. Took me 5 tries. Now I'm S-OFF & unlocked...with the OTA.
Just keep doing it. It'll stick...eventually.
HTC Droid ViperDNA 4.1.0
Amazon Kindle Fire HD 8.9
B&N Nook Color (Laid to rest
HTC Droid Incredible (x2)
HTC Droid Eris
I'm a VZW & HTC baby, & probably always will be.