possibly lost data by "Burning Raw Data CDs"

[dcswest at flashmail.com]

Greetings;

Was running FreeBSD 5.1 Release on a Dell Inspiron 8500 with
a CD-RW/DVD Combo drive and "backed up" data onto several
new CD-RWs simply as follows:

burncd -s max data archive.tar.gz

Then after installing FreeBSD 5.2 Release, tried restoring
as follows:

tar -xvzf /dev/acd0

And unfortunately ended up with only error messages such as
input/output, unexpected end of archive/file and child
returned status 2 from all the CD-RWs too.

Not sure if it has anything to do with not blanking or
erasing the new CD-RWs first or not adding "fixate" to the
"burncd" command, but planning to always now just burn and
thoroughly test ISOs for even one file, and only desperately
seeking to first recover this data any which way.

Thank you very much for any help here,