Why can't I get s=ON on my MyTouch 4g? I have followed the following 2 tutorials on how to unroot and get S=ON on the MyTouch 4g:

http://forum.xda-developers.com/showthread.php?t=834225

I have successfully reverted to the stock ROM and unrooted the phone, but I still have S=OFF.  When I run the first one in the emulator, it gets all the way through execution and tells me to reboot into hboot to get s=ON, but when I do that, it still shows S=OFF:

Duplicating hboot
2048+0 records in
2048+0 records out
1048576 bytes transferred in 0.563 secs (1862479 bytes/sec)
Synchronizing
Powerdown and reboot into hboot to check s=on


I really would like to get S=ON so that I can ask my provider for service if I need it.
This link should help. It contains a link to a thread detailing a special zip file created by one of the developers. It will help you possibly get S-ON. The step by step instructions are in the thread:

http://forum.xda-developers.com/showthread.php?t=863899

By the way, S-OFF isn't something service technicians actively look for. Many people have sent in phones for servicing with S-Off and technicians still fix it. With my Nexus One, once you get S-Off, it shows an unlock symbol that doesn't go away and is shown every time with the splash image during boot. However, many of my friends with this phone have gotten it fixed without problems. 

EDIT: If the S-OFF doesnt work, you should private message or PM the developer who created the zip file on xda. He will be better able to help you as he has repeatedly got S-ON and S-OFF. I dont have the same device. Unfortunately, the bootloaders are device specific and vary on the manufacturer. My experience with S-OFF will be different from yours.