Andy Ott has having a common problem with Duo-Art roll tracking.
He writes, "However, sometimes the paper gets engaged on the edge
of the take-up spool, and disaster then occurs.  I've tried adjusting
the tracking and watching it very closely, but once trouble starts
it usually continues until the roll is seriously damaged."

If the tracking seems to go into a non-corrected state and instead
gets worse, I wonder if the right and left tracking tubes have been
reversed where they feed into the actuating bellows.  Otherwise, I'd
check to make sure the bellows are in good shape.  Perhaps test each
by actuating the little fingers to make sure that each pushes the
paper in the correct direction.

Bill Chapman, in La Quinta, Calif.