Original post by: Gil ,
The give away is the smudge marks you mention when you take the mis-fed paper out. Your rollers are dirty. Even very old low volume printer rarely have worn rollers- I wouldn't try roughing them up the tread is usually quite deep and wear is unlikely. Clean them with someting with mild soap in it and than rinse real well with damp lint free cloth. Sometimes they get dirty from doing a lot of two sided printing the ink on the already printed side rubs off on the rollers ( do you put your already printed one side pages in with the print facing the paper roller? Sometimes its not worth the paper saved for the problems it causes. Also be sure to buy good paper and store un-used paper, sealed in the original wrapper. G.S.