Larry, IF your slide is electric, look at the motor. If it has a lever on the back of the motor, the lever controls the brake which keeps the motor from turning when the slide is IN. There should be a label showing which way is ON of OFF or it may say Locked. If it is in the correct position, then you should not be able to move the slide when it is open or closed using a wrench on the shaft. If the lever is in the locked position and the shaft will turn with a wrench, the internal part of the brake is damaged. That means replacing the motor or the brake itself. If you have mechanical skills, and want to replace the brake yourself, let me know rbdtanasi at yahoo and I will send you instructions on what to look for and how to do it. It isn't hard.
2001 Monaco Diplomat 40' PDQ - 08 Honda CR-V