We got my son a Virgin Pendolino set for Christmas. It's all wonderful except for one thing - it appears that the rear bogie of the power car keeps derailing. It usually happens on points, sometimes (depending on direction) at low speed, even a crawl. I've been experimenting this morning with inclines for a future layout, and it also would go on the uphill round a 2nd radius bend (not sure of precise angle, but I'd guestimate 2 degrees, and it would happen at a constant angle as opposed to a change in elevation at either end). On several occasions it would derail on a simple (if relatively abrupt) stop! No other wheel assemblies seem to cause a problem, just this one.
Fiddling with it, the rear bogie just seems less free than any of the other wheel assemblies, including the front of the power car. Might I have a defective unit? Or is there an adjustment that can be made? Obviously I'm not too keen on replacing the entire set if there is just one bogie issue, but what is the procedure for this sort of thing?