Hi, I am having issues with my KM 8000, When running either 4/4 or 4/0 out of any tray I am getting serious doubling it start's approx 1/4 way down the sheet. Also periodically the sheet will put like a z fold half way down the sheet sometimes causing a jam and sometimes allowing the sheet to be sent all the way through the machine. When the paper jams it look's like it is when the sheet has just entered the fuser. If anyone has had these issue's or have any idea what the problem could be if they would kindly reply it would be much appreciated before I start buying new part's that will not solve my problem. Many Thanks