You will probably need to restore the phone in itunes.
1. Connect phone to itunes.
2. Start phone in DFU mode.
3. Click on restore, and restore phone to 1.1.4.
You then have a few options to jailbreak/unlock/activate, like ziphone/pwnage etc.
And if your phone is unlocked, itunes will not lock it as long as you don't update the firmware. Just make sure you do your reading first before freeing your iphone.