Tambour Shower Door Fitting

A very bizarre thing has happened with the sliding shower door (Tambour?) on our Auto Sleeper Kingham. We came back home after Christmas away without the van  and so I checked on the van today to see if there were any problems. I opened the side door and was shocked to see the whole of the shower door on the floor towards the front of the van well away from the rear shower room. I have looked and stared for ages at the van and still unable to figure out how the sliding shower door not only unattached itself from its runners but then managed to travel those extra feet along the floor.
It is securley parked in a safe place pointing slightly down hill,  the van hasnt been entered so I just dont understand how this could have happened.
The other point that I am asking is how do you refit a sliding door back onto its runners ...any advice welcome.

I'd Take it back to dealer  or to Auto Sleepers under warranty.

John.

I have had this problem. The clearance gap between the runner and screen is to big allowing the screen to fall forward and end up on the floor.
Quick solution is to retain the screen with a suitable stretch cord.
A longer term fix is to reduce the clearance gap with suitable washers and re position the screen stops so the screen is in the curved section of the track in the open position. I still use the stretch cord when on the move.