drivers power seat on 2005 Mercedes-Benz E500

My drivers seat has all the power adjustment setting offered that year, including 3-way memory. Everything works, except the forward/backward lever. the seat only moves 2-inches in either direction. Almost as if something is lodged in the track, but nothing is. I've even tried unplugging-replugging the seat connectors. Any thoughts?

Asked by for the 2005 Mercedes-Benz E500