Reawakening an old thread just to record that the exact same thing happened to my 6700 left hand shifter this weekend. I believe it's the silver tab that was pushed out of position and caused the door to be pushed off - neither of the springs that came out were under much tension. Anyhow, I also found nothing useful on the internet and my poking about was fruitless. Gave up and put an old downtube shifter on so I could get out riding yesterday. I don't think it will be fixed, so will look out for an affordable replacement but more likely just re-adapt to the downtube shifter in the meantime.