Just an FYI - I unlocked when the method for finding the 8 digit code in bml3 first came out. I have since flashed my phone a few times. At least to the Froyo release - maybe a 2.1 i9000 release - but now my bml3 file has FFFFFFFF where the unlock code used to be. The phone is locked again, and the original code no longer works. Recently flashed back to JF6 and then upgraded to JH7 via Kies.
One other developer has discovered this, and started some work on sorting it out. Hopefully more details to come.
Odin Flash Loses your Unlock/Freeze Code - CyanogenMod Forum