Nope, lube isn't the problem but I think I now know what the problem is....( should have read the owners manual first before posting) seems that the sun roof has to be re- synchronized every time the battery is disconnected. Had the car in MB a number of months ago for rear cargo area auto cover problems and I am sure they had to disconnect the battery for that job so will call MB Monday and tell them they forgot the sun roof when they re-connected the battery. Why does a sun roof have to be re-synchronized in the first place, typical over engineering.Desert