Yeah, the wheels were built at my LBS, but re-tensioned by myself since, which could be the problem. I think I over tensioned them, and once one spoke went, to much pressure was put on the others, I snapped a total of 7 during the week, the first 5 at the thread, the last 2 at the elbow, which is where I would expect most to snap.

JJ is correct that it was the book I bought from wheelpro, and whether he bangs his own drum or not, its a pretty clear guide to wheelbuilding.