Reiner Brasch has a PianoDisc that gives a read seek error.  Sounds
like a bad disc drive.  Change it.

Slide the cover open on the diskettes you have tried and look at them
from different angles in a good light.  If there are any scratches on
the disc surface I would throw those diskettes away.  Sometimes a chunk
of the magnetic stuff on the disc surface will flake off and get stuck
on the read-write head.  This will scratch the surface of other discs,
which may flake off and cause more scratching.  If there are scratches
on the discs I would also change the diskette drive.

Moving can also stir up particles of junk that have collected in
out-of-the-way places in the diskette drive.  This can happen to any
disc drive.  I have a $300 paper weight that used to be a digital
camera before it tried to eat a disc.

John Dewey