New Alpine 3720FB, sliding doors won't stay on the track

[sdetweil]

we just picked up our 3720FB on Monday. Drove tue/wed/thur to get home.

Michigan, Indiana, Illinois, Missouri, Oklahoma, Texas.
mostly decent roads, but a few heavily potholed areas.

the front bath has a wall to wall closet with two sliding doors, and a middle latch. we had found the doors off the track on each stop so far.

I think there is just too much play at the top of the door, but if you crank the rollers up tight, the bottom guides won't reach. I'm thinking some kind of nylon bushing on end screwed to the top of the door to be the space consumer. maybe 3/4 to an inch long.

the Montana 3900fb has 4 doors. (I do have dual tracks installed for front and back doors, both top and bottom)

anyone seen a similar problem and a working solution?