hi Michael, i have had this exact problem with front nuovo record brakes on two different bikes that i use year-round. maybe it is similar to what you are experiencing...
the culprit was not the eccentric quick-release mechanism itself but rather the brake's main pivot bolt. over time road salt and dirt led to an increase of friction in the brake caliper; almost as though the adjustment was over-tightened.. since the caliper was slow to return to fully open position, the tension of the main spring was effectively reduced. this spring tension is important to the function of the QR and without it the release can flop open with vibration during braking...
cleaning and regreasing the pivot assembly solved my problem
andrei padlowski brooklyn, ny convalescing in connecticut
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>The design of this thing is such that when the QR is fully closed, it is
over center in such a way that tension from the brake cable cannot cause it
to open. If it's all assembled correctly, then the only possible answer is
that for some reason, you're not closing the QR fully. Dirt or wear could
be the culprit, or there's something else that we don't know about.
Never seen a Campy QR open under braking. Suggest you disassemble, clean and re-grease, and re-assemble correctly.
Mark Petry
Bainbridge Island, WA