First blow out occured just after dropping from 70kmph after flattening out off a hill. The road was pretty rough, but I don't think I hit anything. Second blow out occured after I'd just patched my tube after a puncture (I'd already used my spare tube). I was cruising easy on a wet road and then bang! The puncture was on a seam so that could have been it. I've ridden on a Vittoria with ten patches and I never had a worry. But you are right, it could have been an installation issue. You are welcome to the continentals, I'm too scared to use em!