- Oct 8, 2011
No I'm using another carrier SIM and I still can unlock it. Actually the process is pretty simple, just so much time for download files (I didn't wait 30 mins before unlock).
What is the manufacture date of your battery? Take out the battery when it's powered off and check on the back. Mine for example says 2013.06.25(L) in a white field near the bottom. I believe it was devices whose batteries were made in June or later are of a different revision which locks the bootloader more securely. However, if yours was made in June or later, there may still be hope yet!
I've all since given up on ever unlocking the thing, especially since I got a different phone, but I'd be willing to try again. For science!