its been a while since i used a powertap on the track- and it was one of the old yellow wired units... i do remember turning off the Auto Zero..
does not being able to kill the Auto-Zero make that head unit unusable? i was under the impression that the auto zero on a PowerTap only actually happened when the wheel was spinning but the cranks were not(ie Coasting)? and thought it needed 5sec to complete.. since you can never do that on a track bike... does it ever actually attempt to auto-zero?