If you previously did 1800 mg/day of ribavirin a day for 72 weeks, maybe either the ribavirin
isn't the problem at all, i.e. pre-dosing
isn't the answer -- or, you're not absorbing the riba very well, a crude measure of which would have been your hemoglobin response during treatment.
Anyway, taking the pre-dosing out of the equation, it seems that the only thing you're doing different this time is swapping 72 weeks of Infergen for 72 weeks of SOC.