What exactly is your handset doing? is it completely dead? are you getting flashing red lights in the infrared port? have you tried reflashing main? try updating your EROM. Use wotan server for this. It does it for free.

a note about the IMEI. you cant change the IMEI. Its illegal and you can go to prison for this. so dont do this or question how to do it. and others please dont suggest it.