Had the service tech. Out to look at my problem. He showed me exactly what was wrong and explaned how to fix it. It seems that the counter sink holes in the nylon slide bar break out allowing it to move in or out causing the problem. The slide bar has to be replaced. To do that the slide needs to be extended beyond it. This requires removing the trim around interior of the slide. About a four hour job at the dealership. He was able to reposition the slide bar and put in a few screws as a temporary solution.
I also talked to the warranty department at Sabre who gave me a slightly different fix. They will address this problem with me at the International Rally next month.
2012 F250 Super Duty
2013 Sabre 33CKTS