I get the same thing once in a while on takeoff. I switch off NWS at 50-60kts, always very gentle with controls on takeoff roll, rotate at 120-125kts, rotate is measured and deep. The nose wheel break is very rare, but tends to happen around the 90-110kt range, just before I start rotation. I normally have a pretty decent load on (Who doesn't on takeoff?), but there seems to be no correlation between field condition and nose wheel failure.