Joined: Jan 2009
Posts: 43,974
Likes: 6,156
From: New York, NY, and High Falls, NY, USA
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
The hanger moves because the dropouts are not parallel. I can't think of anything else that would cause that.
Your LBS can do both of these alignments for a total of about $10 to $20. It's totally worth it. The dropout tools are $85, and the hanger tool is almost as much.