Are your slides electric or hydraulic? Assuming they are electric rack and pinion, try lubricating your the rack gear under the slide, then run it in and out a couple of times. Also, have someone run the slides in while you are outside watching. Be sure it is not out of adjustment as it is traveling. Pull the slide in until it likes 6" or so closing, then measure each side top and bottom and make sure it isn't cockeyed. Lubricating the gears would be the first thing to try, though. Unless you are badly out of level, that won't keep your slides from operating.
If the slides need adjustment, your dealer should be able to take care of that under warranty. I've never had to adjust my slides, but it doesn't look like it would be that hard to do.
Edited by: mike06081969
Mike in Tennessee
2007 Cruiser 30QB
2008 Ford F250 Lariat 4x4 6.4 Powerstroke
Valley 16K slider
Ride-Rite air bags