CD burn trouble

[The Hoelschers]

Anyone want to try a hand with the following error?  I get this
(ultimately from CDRECORD) using just about any front-end (X-cdroast,
cgombust, gtoaster), and the burnt disc is useless.  Trying to mount it
gives an I/O error.   (bash: cd: /mnt/cdrom2: Input/output error)

I'm running Mandrake 7.1 stock (except I updated gtoaster to latest with
no change).  I'm trying to burn an ISO image (Red Hat 7.0)

I'm thinking I may have a bum ISO download, but don't know how to check
that either.  Should I be able to mount the ISO as a loop device and
"see" the tree structure?  Anyway, the error message ...  I should
mention that this comes after 100% burn and the drive is ejected (in
other words, it looks like it's done everything good, ejects the disc,
then errors after I re-insert the disc).

 Track 01:   0 of 639 MB written. Track 01: writing  30 KB of pad data.
Track 01: Total bytes read/written: 670464000/670494720 (327390
sectors).
Writing  time: 1222.276s

** Editorial note: the drive ejects at this poing, the dialog says 100%
complete, but the STOP option
** what's still available, not OK.  If I hit STOP, then "stopped at user
request".  If I just re-insert the
** disc, then it spits out the following and finishes (closes the
progress dialog box).

CDB:  00 00 00 00 00 00
Sense Bytes: 70 00 02 00 00 00 00 13 00 00 00 00 3A 00 00 00
Sense Key: 0x2 Not Ready, Segment 0
Sense Code: 0x3A Qual 0x00 (medium not present) Fru 0x0
Sense flags: Blk 0 (not valid)
/usr/bin/cdrecord: Input/output error. test unit ready: scsi sendcmd:
retryable error
status: 0x2 (CHECK CONDITION)
/usr/bin/cdrecord: fifo had 20461 puts and 20461 gets.
/usr/bin/cdrecord: fifo was 0 times empty and 20064 times full, min fill
was 96%.

Thanks in advance -
Chris.