Interesting, I have only noticed that once. I use a Stages Gen III (non drive side) PM. I've only had it for about two weeks. My cadence numbers have been spot on except for this one incident where I really hammered it on a sprint. Do you think there is a relationship between the amount of power and higher than normal cadence? I wasn't spinning (at least I thought I wasn't...I was in a pretty big gear and it certainly did not feel like I was going above 120RPM.