EKW -- good luck! I've lost some ground then plateaued myself, shaking up the diet and off-the-bike exercise program.

Drew Eckhardt & Tundra Man -- I think you're both right. The one (or several) broken spoke(s) creates an extra stress on other spokes that spikes their fatiguing and/or is often enough to push the accumulated fatigue over the top. Peak & cumulative combine.

All -- since we're drifting into all this spoke-ology / metallurgy talk again, let me ask a question that I've heard kicked around but I don't know what the gospel is: for a heavier person, interested primarily in durability (not racing performance, pinching a penny, etc.), which is best -- single-butted or double-butted spokes? There are confounding issues with regard to strength, tension, elasticity, etc. What nets out best?