I saw an offer for a dual G4 1,42GHz daughter card with the original radiator. This would be quite an upgrade for my single 2003 model 1,25GHz G4. The seller tried to upgrade his stable running dual 1GHz G4 MDD from 2002 with this card but he can't even boot with it because it causes problems with the RAM. Only the 867MHz G4s had a slower system bus. What else could cause these problems? The ROM perhaps?