Had the same phone, same problem. I had no luck unlocking the bootloader the official way. While the code worked, when it asked me to say yes/no to unlocking the bootloader, I could not confirm yes, only no.
Instead, you need Revolutionary
to set S-OFF. My device was HBOOT 1.16, so yours probably is to. Therefore you'll need to downgrade HBOOT to 1.13 first. Get information on downgrading here:
[TOOL]-[9 Jan 2012]S-off for HBOOT 1.16.0000 v2.1 - xda-developers
After you downgrade and run the revolutionary tool, your phone will be in the free and clear. This process does a non-China factory reset, and results in you having the European rom.