No, I am not shifting intentionally while pedaling backwards. But, for example, I pull up to a stop sign and pedal a quarter turn backwards to get the pedal on top and ready to go, frequently the chain will shift to the next cog, or maybe two cogs... I put the bike on the stand and played a bit, I found it happens in a similar part of the chain each time, but I don't see anything bent or damaged. I oiled the chain really well to make sure everything was smooth, still happens.

I'll also say, the bike shifts perfectly when pedaling forward, I have no problems there.

I'm not sure this is a problem other than being really annoying, but I'd still like to know what the problem is and fix it.

Any ideas?