Went on a short ride today, but the problem is very persistent. Especially when starting in the small ring. I also suspect that the chainline in that gear is pulling at an angle, and the momentum very easily pulls the right side out of the dropout. I'm running a Hollowtech II Shimano bottom bracket with a 9-speed compact Tiagra Chainset and a 10-speed cassette in the back. So when in the small ring and the bottom part of the cassette, the chainline is pretty angled. I definately need to try a pair steel skewers.