My Dell 1710n started making these very subtle imprints.   They are roughly 2.5" from the right side of the page and very small, only about 1/4" long, repeating every 1 1/4".

I have recently replaced both the toner and the drum.  The marks appeared before and still to continue to appear after.

And just to be clear, this is NOT toner marks.  This clearly is an impression on the paper being printed out, like something is on a roller somewhere.  I just don't know where to start.

Can anyone point me in the right direction ?

Thanks.