I would bet a cold beer you will find it to be what I posted earlier.
One thing I don't quite understand though. Unless Sunnybrook changed something on the Titans in 2005 from 2004, the shaft, motor, and gears for the slide should be in the open below the enclosed underbelly. You should be able to see the runners with tooth openings that the gears mate with on the slide bottom, and also the shaft that comes out of the motor that has probably slipped out of its slot located under the trailer, but outside of the black enclosing material.
Before you spend all the money on a repair shop, I would crawl under there and take a look. It is a very simple and easy repair if your trailer is like mine, and I believe it is.
Barney