Bub, that thin notch isn't the one that stalled. The one on the left in the picture is the culprit. I need to stay more alert when I'm notching. I was revelling in how long and narrow that other one was when suddenly I got nothing on the other one. It wasn't quite as narrow as the other one and opened up at the base as I kept trying to get a flake. I think I could have widened it a little and unstalled it, but decided to let it be and go with that. I'll eventually get it right. Thanks for the help.
George