One of our HP Laserjet 4100N's required a new maintenance kit. I installed this including the new fuser, and new transfer roller, however the new transfer roller appears to cause the toner to stick to the roller and smear one side of the page, whilst leaving the other side blank. I changed the transfer roller back to the original and it appears to print the left half of a document correctly and the right hand side appears to be fading from the centre out to the edge where it is barely visible. I tried a couple of different fusers as well to see if this would solve the problem, however there is no change. I've also reset the warning message. Can anybody suggest anything to fix this problem?