Subaru Repair: Outback Engine Problems, head gasket failure, car reliability

Question
The Apr 07 Consumer Reports on Car Reliability (page 92)shows uncharacteristically higher than average major engine problems for 01 and 02 four cylinder Legacy & Outbacks.  Is there a known problem with these engines?  

Answer
L/S Head gasket failure leaking coolant externally .Subaru came up with a  coolant conditioner that seems to help and stretched out the head gasket warranty to 100k if you had the conditioner put in.Not all of them exhibit this problem,and honestly the ones that weren't maintained all that well seem to be the ones with the most problems.