There should be no vacuum to the tracker during rewind.  If it tracks
perfect while playing then the problem could be that it's out of
adjustment.  I usually take a really good recut and put it on the
piano.  With no vacuum to the tracker unit the roll should play fine.

If you are playing rolls and the tracker is always moving the roll to
left on several different rolls then the tracker is out of adjustment.
If it stays to the right while playing several rolls then it is out of
adjustment.  If it barely shifts a little to the left and a little to
the right once in a while then it is correct.

It is best to play some new rolls to test it.  Always tap the loose
roll to the right flange.

Don Teach
Shreveport, Louisiana