[lug] Hardware/Software Puzzle

[Paul E Condon]

I'm having serious problems with my cdreader and cdburner/reader.
When trying to figure out what is happening, I have been using
md5sum to determine whether or not I have a true copy of a CD.
My reader is on /dev/hdc and reader/writer on /dev/hdd
I get md5sums with
md5sum /dev/hdd 
and 
md5sum /dev/hdc

This seems to work for CDs that have been manufactured by publishers.
For software CDs from, e.g. Intuit, I always get the same md5sum on
both reader and reader/writer. But for burnable CDs, I always get an
I/O error on the reader/writer and I get a different md5sum on every
re-read on the reader. How can this happen? I have old burnt CDs going
back to 1996, and as recently as today. They all behave the same. They
were burnt on different equipment, some by other people. Is there
something wrong with my command above? Have I forgotten a necessary
command option? Any ideas?

P.S. This happens of three different Debian boxes all running Etch.

-- 
Paul E Condon           
pecondon at mesanetworks.net