Apple Logic Pro /LogicExpress Discussion

Logic will not launch core audio. When I selected the Metric Halo driver 
in the audio driver setup window Logic crashes. At the suggestion of 
Metric Halo tech I installed an updated driver. Logic cannot see the 
driver in the setup window. If I choose built-in audio Logic crashes. I 
have tried throwing out Logic prefs. This all started after my computer 
died and I had to hve the logic board replaced. I'm still stuck, Help!

G4 1.25 dual   Mac OS X (10.3)   Metric Halo 2882

Thanks,  Lee