My post on the other forum (L&B) maybe one that you are referring to. The issue with mine is almost certainly that one of the rear pickups is not sitting flush to the underside of the loco, whereas the other one is, hence I am only having issues when the loco turns one direction and not the other. I guess if I can find a way of making the pickup sit flush it may solve the issue.
Haven't tried running with a train yet (because I haven't risked altering the couplings), but in my opinion if this does help it is not a solution, only a workaround. The loco should run properly both light and with stock attached.