That's interesting, I'm a minimalist guy for 10+ years even though my PT disapproves of it, and all the injuries I've had have always been in my hips. Never had a single injury - not even a niggle - in my feet or calves (knock on wood).
My take on this is that the minimalist shoes have made my calves and below stronger and therefore more resistent to injury but i dont really know.
And actually, the only time ive ever had my calves/achilles act up, was when I tried to transition to "normal" shoes - they were Nike Pegasus Turbo 2's. I made it about 30 miles in those shoes and my calves were screaming at me to stop the whole time.
For what it's worth, I think you should run it what feels best, not just because a guideline or what someone says.