I'm sure technique is important. I know that as I get older I'm finding out more and more how important bike fit is to making it possible to ride without pain showing up 30 minutes after I start.
There is a series of articles in VeloNew's coaches panel archives from a couple of years ago discussing a riders efforts to get where he could ride without severe knee pain. The link below if for the article about his trip to the Bolder Sports Medicine Center for a fit. I found it very interesting. Makes me wish I could afford both time and money to take a week off, pack up the bike and head to Bolder to see what they could do for me.
VeloNews - Coaches Panel