Have you flash the BIOS with the BIOS modded by 911medic? If yes, then you check with rw-everything is your slic already 2.1? If yes, then download the certificate and insert with "slmgr -ilc certificate" and insert key with "slmgr -ipk ultimate keys"
You can use COMPAQ-HP certificate, just make sure after you flash your BIOS check the SLIC with RW-Everything
Flash from DOS with the flas**t. Some other flash tools apparently do not allow updating the slic code..