Originally Posted by TurbineBlade

Hanger is good - I put the tool on it last week.

Actually, I think (from reading) that most bikes do this since derailleur drive trains are meant to be used in the forward direction only. Fix is to stop backpedalling. I think the cause is simple chainline angle. Every once in a while I'll backpedal just a half kick or so, and then start at the traffic light only to have a "pop" sound because the chain tries to grab a different cog.

Disregard- Thanks to the above posters.