we have just come back from our trip . Caravan towed with no problems . our last caravan had ATC on it and we never had a problem towing in this country or in Europe , on and off ferries . when we away three weeks ago we couldn't move the van with the motor mover .we were able to tow to go away . So on our return took it straight to dealer . Because we would be unable park it in our storage site with out the mover . We thought the fault was the mover. So they kept the van and adjusted it. We picked it up from the dealer and have been away until yesterday. We arrived at storage and unplugged it from car . But it wouldn't move with the mover . It would go backwards and side ways but not forward. We couldn't put on the wheel clamp . Tried to hitch it and pull with car but it was locked. We went to our dealer. Speaking to their engineer . He said it's not the mover it has to be the ATC . We tried to carry out a few things as advised . But this didn't work . We have arranged for them to come to our storage site now. i did e mail Alko . Explaining that we would be towing to Europe in the spring and what will happen if it locks on route or on the ferry . Alko e mailed me back and said the dealer needs to sort out our problem but advised me that when going on to ferry I need to unplug the ATC due to movement of ship and going over ramps to board. I can't believe this . And wondered if anyone else does this or has had a problem. after a sleepless night thinking about it we were able to release it and get it moving . But we are now concerned about this happening again when on the road or if going on a ferry . We shall ask if it can go back in for a diagnostic check . my question is do you unplug your ATC when boarding a ferry . To prevent locking .