Sharp DVRW260 player / recorder problem

First of all, sorry if this isn't appropriate to this group.

The school at which I teach bought a new Sharp DVRW260 DVD / VHS player
/ recorder a few months back. It was purchased primarily in order to
copy our (fairly extensice!) video archive from VHS to DVD, and
secondly in order to play DVDs and videos in my classroom. It's not
connected to an aerial, and it's actually attached to a data projector
rather than a TV, FWIW.

However, I've consistently had a problem with the machine. It has two
record modes - dubbing from VHS, and OTR (which isn't set up work from
the VHS player). OTR seems to work perfectly when recording from a
broadcast signal (albeit with a very fuzzy picture, as you can
imagine!), but nine times out of ten dubbing from VHS results in a
"disc error C211" message as soon as the confirmation window is
completed in order to commence recording. This is supposed to mean that
the disk is scratched, yet the same disk will then record perfectly on
OTR.

It goes without saying that we've tried (three) different brands of
disk (Imation, Apple and something obscure), and that we're using the
correct (DVD-R /-RW) disks for the machine.

Tonight I've even tried linking inputs / outputs in the hope that I
could use OTR from the VHS player, only to find that this too gives a
C211 error when the tape is playing!

We've had the machine replaced without inspection, only to find that
the replacement seems to have a marginally poorer success rate than the
original. The replacement was then returned to the supplier, who
claimed that the machine was fine "but some of your disks were
scratched". Yeah, right...and that explains the OTR / dubbing
disparity, of course.

I'm posting this mainly in the hope that someone may have some ideas
about the cause, or that someone may have experience with this
particular machine. Googling seems to provide nothing more than sales
material, unfortunately.

I'd be gratful for any advice (especially since I know nothing about TV
/ video / DVD, and don't even have a TV at home!). I'd also suggest to
anyone considering buying such a machine that they might wish to
consider an alternative...

TIA

--
Simon
www.simondaw.freeserve.co.uk

Simon D