I have had a similar problem in my street rod. The column is a locking column with the switch mounted about half way down the column. Somehow the gremlins get in every few months, and move the switch a tiny bit causing starting difficulties. It's a bitch to re-set to get it right, but the good thing is there are only two screws to tighten once you find the right position. One of these days I'm going to get rid of that old column and replace it with a new one taht doesn't have the locking mechanism and the ignition key. But until then guess I will just have to tweak it from time to time.