I've seen cases of front wheels being poorly aligned on bikes, mostly lower end stuff. I purchased a lightly ridden Raleigh Capri from a friend who never crashed it, but the front wheel was not well aligned in the fork dropouts. Close inspection revealed that one of the dropouts was not parallel to the front/rear axis. When the wheel was tightened, it would cause a twist in the fork blade and the wheel would go off to one side. Straightening the dropout resolved the problem. I experienced a similar phenomenon after cold setting the rear triangle of my Schwinn Super Sport. Rechecking and adjusting the parallelism of the dropouts solved it.