Friend, You're talking about the Lock Code, right? Actually, flashing your N900 won't help either (the lock code won't go back to the default of 12345). There is a thread here which talks about the steps needed to extract an "encrypted" version of your lock code from your N900, and then using a decrypter application available in Linux (such as John the Ripper), so that you can recovery your lock code. Here's the thread, hope this helps: http://talk.maemo.org/showthread.php?t=37808&page=33