@BioWheel, just curious - where did the spokes fail? In the middle, near the hub or near the nipple? My experience is that the location of the failure helps explain what's going on.
If you've never had problems with alloy rims but seem to break spokes with carbon rims, keep in mind alloy will bend/flex but carbon won't. Whatever weight savings or compliance you get from using carbon rims is outweighed by having to replace spokes more frequently because the carbon rim doesn't flex at all compared to the alloy rim which can flex quite a bit and take more stress without issues.
Also, it's very difficult to achieve completely uniform spoke tension across the board when you're building a wheel. The tool you're using can impact results. I found the Wheelsmith tensiometer much more accurate than the Park, for ex. I always found it better to eliminate outliers (say any spoke that's more than 10% different than the others) and concentrate my energy there rather than trying to make them all the same number.