This worked for me on a 3800: Use a lint free cloth that has been very lightly moistened with tap water and a clean unused toothbrush. Swab the big rubber roll as far as you can reach, and gently brush the now damp roller. Keep pressing the paper feed button repeatedly while doing it so that the entire circumference of the roller gets treated. Prior to that I had to put sheets of card behind the paper so that it was nearer the grab roller. Since the cleaning regime the printer has been fine.
Regards,
John